I posted this in another thread but thought it deserved its own......
I replaced just about every bulb in the car with LEDs from superbrightleds.com. Heres a run down of all the PNs from there site:
DRL (2) - HB3-WHP28-DRL
Turn signals (4) - 7440-A45-T Amber
Reverse lights (2) - WLED-WHP10 Cool White
License plate (2) - WLED-WHP5 Cool White
Dome light (1) - 3022-CWHP4 Cool White
Map light (2) - 3022-CWHP4 Cool White
Trunk light (1) - WLED-WHP5 Cool White
Vanity light (2) - 3710-CWHP3
Flasher for turn signals - CF18-08 8 Pin Black Toyota Flasher
Do not try to install 7440-A3W-G for your turn signals....they will not fit through the hole in the housing. I found this out the hard way and had to return them.
The vanity lights needed to be somewhat forced in because the diameter of the bulb is slightly larger than the stock bulb. They work and stay put once you get them in there, but it requires a little force.
I didnt change anything with the fog lights... I dont really care for the overly bright and excessive headlight look. The LED headlights are plenty bright enough (almost too bright). Subiespeed sells an OLM fog light kit that replaces the entire housing/lens.
Provided by Rainking:
High Beam Headlight: HB3 (9005)
Low Beam Headlight (w/out LED headlights): H11 (H8, 881)
Parking Light (w/out LED headlights): W5W (168/194)
Front Fog Light: H16 NOTE: Owners manual is WRONG. 2015 WRX & STI use PGJ19-3 base as opposed to the 5202/9009.
Front Turn Signal Light: WY21W (7440)
Front Side Marker Light: W5W (168/194)
Rear Turn Signal: WY21W (7440)
Backup Light: W16W (921, 955, T15)
Rear Side Marker Light: W5W (168/194)
License Plate Light: W5W (168/194)
Cargo/Trunk Light: W5W (168/194)
Map Light: DE3175
Rear Dome Light: DE3175
Visor/Vanity Light: 6614/6614F 6641/6641F NOTE: Owners manual is WRONG. Visor/Vanity Lights are 29mm fuse-style bulbs
Hopefully this can help whoever is looking to replace their halogens with LEDs.