These are hacks that I consider essential -- they fix known bugs and stupid things in the game!
TwoJeffs at Simbology
Various Bug Fixes
Various Annoyance Fixes -- I recommend most of them!
Various No Autonomy Mods -- Kill your pet peeve autonomous actions!
Various Baby/Toddler Fixes -- At least get the Potty Fix so the maid can clean the potty and the toddler can pee in a dirty potty! No Smart Milk Drag is also great -- you can put all the Smart Milk in the toddler's inventory for later consumption.
Various Want Hacks -- Prevent the want that annoys you most.
Various Food Hacks -- I recommend all of them!
Various University Hacks -- I recommend most of them, especially the College Adjuster (another general fix it tool) and the Stinky Dormie Fix (best assignment litter fixer yet).
Always Flush Toilet -- Just what it says.
Baby Wants Fix -- Adoption and birth satisfy either want.
Caged Pet Fixes -- Fixes a bug where parrots and womrats would virtually consume food while the game was paused or in build/buy mode. The result was often no food left when play resumed and the pet would die before you could feed it!
Crystal Ball -- Skip the gypsy, just buy her crystal ball! Same price, but reusable. I like to put it on a community lot, so they can start a date immediately.
No Pet Code Unlock Spam -- Stops the huge lag when a pet gets promoted and unlocks all the special items.
No Pet Obsession -- Keeps Sims from autonomously playing with pets that they do not own and are not friends with.
School Bus/Bring Friend From School/Homework Hacks -- Reduces school bus spam. Better friend choosing and new dialog. Less homework for kids with good grades.
SimBlender -- A workhorse! Includes many features previously only adjustable through SimPE, as well as a general fix-it tool.
Smart Beds -- Finishes a half implemented Maxis idea to get Sims to sleep in the same bed every night! Has several plug-ins and a stand alone Community Sleep hack.
Teens Keep Loves -- Teen sweethearts keep their crushes into college or adulthood.
Visitor Controller -- Prevents undesirable visitors (configurable).
Welcome Wagon Hacks -- Welcome Wagon asks permission before they show up.
I can wholeheartedly recommend all of Lord Darcy's fixes!
Stuff Pack Objects Fix Collection for Apartment Life -- Giant Maxis repair/update pack! If you don't have AL, there are links to previous versions of many of the repairs in this collection.
TV2TiledRepairAnimFix -- Keeps the Sim from holding the screwdriver backward.
MotiveFix_Shower_Tub -- Gives all showers and tubs the maxium Hygiene and Comfort boosts.
MotiveFix_Bed -- Gives all beds the maximum Energy and Comfort boosts.
More Decorative Slots -- Allows more objects to be placed on and in Maxis objects.
PieMenuTextStringFix -- Repairs some minor typos in the US/UK English menus and several more in other languages.
Celebration & Custom Cakes can be placed in OFB Decra-Chill Food Display -- Just like it says.
Pet Interactions Enabler for Forgotten Objects -- Just like it says.
Stuff Pack Objects Fix Collection -- Fixes a lot of SP stuff.
FreeTime Wall Phone Ring FX Fix -- Visual portion of sound effect like the base game phone.
Maxis Modular Stairs Passage Fix -- Lets Sims walk under modular stairs.
Maxis Centerpiece as Centerpiece -- Allows Sims to place their plates on a table with a centerpiece.
Targa SupaFridge -- Gives all fridge functions to the mini-fridge.
Lord Darcy at MATY
Decustomized and Updated Maxis Official Objects/Clothing -- All the preorder items, now appearing with the other items from that EP, with added functions from newer EPs.
Lord Darcy at DJS Sims
Newer EP-ready versions of JFade's Community Lot Stove At Home and Exercise Only TV which also use all installed recolors of the original Maxis items.
Smarter-Lights -- More sensible light behaviors.
Diploma-Hides-With-Walls -- Prevents your diploma from hanging in mid-air.
SlotEnablePackage_Counters -- Allows small appliances and cash registers to be placed diagonally on otherwise unusable inside corners.
Mary Lou at MTS
Counter-Friendly Appliances -- Allows the sides of the cabinets to hide the appliance "installed" inside them.
Full set of Maxis adult female meshes with Fat and Preg morphs.
Warning: May conflict with Sexyfeet or Warlokk's XHi-Res meshes.
Fanseelamb at MTS
Maxis everyday coats as outerwear.
Inge Jones at MTS
The gizmo that makes portals visible will allow you to move the mailbox without moving the portal under it. No more carpool driving across the lawn! Tip by dark_author at Simbology.
Inge Jones at Simlogical
Nanny Detection, Musical Crib Fix, CribGetOutAll, NoAutonomousReadTo -- Inge has several other baby and childcare hacks, but these are the ones I use.
PushedGreetPatch, NoSetUnlockedPatch -- Sims autoanswer the doorbell; improves the whining about stuff behind locked doors. Many other neat doors and locking systems.
Apartment Fixes -- Makes the other tenants act more sensibly.
ShinyTimeNPCEverywhere -- Spawns a cafeteria worker on residential/apartment lots.
NoAutonomyFridge -- Prevents snacking unless starving.
Treeag at MTS
Hide the ugly Sims in the SimBin!
Tan Overlay Fix for Oddly Shaped Meshes -- Sims using BodyBuilder meshes (or any other mesh using a non-Maxis UVMap) would have untanned patches -- but JFade has fixed this!
Leesester at MTS
Use any door on your apartments!
Chris Hatch at Back Alley Sims
Genetic and gender specific baby hair!
Goggalor at MATY
Shiftable signs, paintings and photos (AL)
Argon at MATY
Repaired Cper and Csla Archtypes
Instruments by proxy GUID -- Makes musical instruments perform together. Replaces Atavera's hack.
Niol at MTS
Roof Mod -- Causes roofs to appear in their true colors
Warning: Causes the Maxis roofs to appear too bright/light
Maxis roof recolors and replacements -- Recolors and replacements for the Maxis roofs compatible with Niol's mod.
Dress Me Correctly -- Sims will dress for work, school, or bed after their showers.
Dress toddlers correctly too! -- Toddlers get their jammies or normal clothes on after getting cleaned up.
Fixed Rat Race Magazine -- FT broke it; MogHughson fixed it!
Pets and Children Share Bed -- Ok, it's just cute! But you gotta have cuteness...
Apartment Lot Incoming Calls -- Fixes error from incoming calls to apartments.
Si'Down with Your Drink -- What it says.
One-Tile Job Notice Board and Two-Tile Job Notice Board -- Lets your Sims get a job in any career.
The Thirstiest Bath Mats -- No more puddles to mop up!
Maxis bathmats made thirsty -- Replacements for the Maxis bathmat and kitchen rug.
Worf_84 at MTS
Close Bird Cage When Done -- Recommended by BoilingOil, this hack makes the Sim close the cage door after playing with the parrot.
Cyjon at Cyjon's Sims 2 Mods 'n' Stuff
Practice Perform Changes -- Recommended by BoilingOil, it complements his Music & Dance fixes.
Better Roach Stomp -- Stomping really kills the buggers!
Relationship Decay Fix -- Fixes Maxis bug calculating relationship decay for members of large families.
BoilingOil at Leefish.nl
Alien Abductions:
P4A - Alien Trigger Override -- Revised Pregnancy For All which works with Alien Experiments.
Alien Experiments -- An alternate alien abduction hack. Pregger ain't the worst thing that can happen!
Multi-PT #4 and #8 -- Multiple Polination Technicians to provide some variety in your alien offspring.
Aliena Impregnata -- An alternate PT.
Baby, Toddler, and Child Care:
NoAuto Toddler Bathing -- Just what it says.
No Lecture Baby -- Prevents all lecturing of babies. They aren't controllable yet, so it's not their fault!
Feed Baby -- Better breastfeeding!
Feed Baby Plug-ins -- Modifies Feed Baby to allow nursemaids and prevent bottle feeding when mom or a nursemaid is available.
Children get Bottles -- Kids can help mom by getting a bottle for the toddler.
PlanMaternityOutfit -- Allows your Sim to plan his or her maternity outfit before getting pregnant.
Food:
Food Dish Autonomy -- Automatic storage of leftovers.
Espresso for Visitors -- Lets visitors make and serve espresso.
Social:
Phone Make-Over -- Combines, enhances, and fixes several popular phone hacks. If you prefer JMP's phonehack, get BO's fix, PhoneCheckFix.
Social - Kiss Cheek -- Prevents the bug in the Maxis function.
Step Family Romance -- allows step-siblings to become romantically involved.
Stay Late -- Teen and older visitors will stay until all residents are asleep.
Better Lost Friend Notification -- Tells you which Sim lost the friend.
No Naked Emitters -- Finally, no shock response when there's a naked Sim around!
Hobbies:
Sellable Car -- In-game sale of restored cars.
Music & Dance Fixes -- Combines 4 popular hacks!
University:
Remote Dorm Doors -- Sims don't need to be standing by a dorm door to claim it.
Pets:
No Animal Control -- Prevents Animal Control from taking pets from families whose oldest member is a child. Also requires a No Social Worker hack to keep the child on the lot.
Moody Birds -- Bird will only consent to being played with for a couple hours.
PetBedsSatifyWants -- Fix for Paladin's 1 tile pet beds.
Misc.:
Unlimited Sims -- Allows more than 8 Sims in a family.
Reward Catalog -- Lets the family share their aspiration points.
Names -- Lists of names from several hacks combined and culled. No more duplicate names!
No Trash Memories -- Configurable hack to prevent trash memories from ever happening!
Spawn Objects -- Creates a copy of your favorite "fix it" objects on community lots.
No Sim Loaded -- Cleans up quite a bit of trash data.
Pixelhate's FullPoster Wall Overlays revised -- Allows you to apply a border to any wallpaper.
Vacation Actions Limited -- More sensible autonomy for the Vacation dances.
Squinge/Chaavik at InSim
Casual Dress For Work -- Sends Sims to work in their Casual clothes.
Pregnant Sims Wear Any Outfit -- Pregnant Sims wear their normal clothes. Make sure they have something with a pregnant morph to wear before knocking them up!
Tunaisafish at MTS
Attraction Traits Fix (V1.06) -- Repairs the most obviously borked parts of the Maxis attraction system.
SmartDoor v0.108 -- BoilingOil recommends this over the SimLogical doors! Doors can be used to keep customers and/or employees out of the household portion of a home business as well as the obvious uses.
Simsfreq at Simbology
Co-Sleeper -- Allows babies and toddlers to sleep with their parents.
More sensible lights for Maxis lamps – Base Game
More sensible lights for Maxis lamps – Pets/OfB/Seasons
Door/light fixes -- Doors will let in appropriate amounts of light.
NPCs Wear Casual Outfits -- for people who can't get NPC Replacer to work.
MsBarrows at TSR
Nursery Fixes -- Fixes UVMap error on Maxis crib and the changing table uses the crib recolors.
Value Counter Fix -- Fixes UVMap error on corner counters.
Formula Fridges -- Countertop fridge for formula only.
Free Time Nursery - Bedding Match Set -- Freetime cribs and changing table use base game crib bedding.
Free Range Cereal Bowl -- Rechannels the toddlers' urge to eat dogfood!