Wish I had tint... anyways:
1994 Legacy Sport Sedan, ~227,000 km (Canadian version / no automatic deathbelts) / 5MT / white: Purchased for $3800 almost 3 years ago.
Removed snorkus / enlarged fender airbox entry hole to 3" / added 3" PVC 90 degree elbow in fender to direct air in from foglight hole / removed foglight blocker
Target Coffee cup mod (Unspillable!)
Rebuilt / hybrid stock turbo with T-bird compressor wheel & housing (not that much of a difference IMHO)
TurboXS bleed MBC (to be replaced with a $10 ball-and-spring hardware store MBC, already built) running at 9psi due to a worn clutch (usually 15psi)
WRX black hoodscoop (to feed my old Saab 900 TMIC, or should I say, interheater) - now just directly cools the turbo / chimney / engine compartment
Izuzu FMIC from eBay, all kinds of custom work to mount and route. Bumper's cut, headlights are spaced out bug-eye style. Now with piping that doesn't blow apart!
Dremeled turbine exit and exhaust entrance for minimized backpressure
3" custom mandrel-bent downpipe, 3" custom press-bent exhaust all the way back to 2.5" dual exit muffler that came with the car (has been flared / enlarged to seat the 3" exhaust)
Eventually, the Hooker 3" glasspak I have sitting in my truck will replace the stock muffler.
Coolant tank relocation to old washer bottle location. Washer bottle removal, replaced with Ford washer bag behind passenger headlight, hung with zipties.
Diamond coil pack
Updated / white wire knock sensor
Autometer Phantom boost/vac gauge, narrowband a/f ratio, and 0-1600* F EGT gauge with type K thermocouple drilled and clamped into preturbo header piping
Surplus (Skycraft) marine voltmeter ($5)
Autometer Phantom fuel pressure gauge with failed pressure transdeucer, older model so must buy new one...
Rocky Mountain Radar RMR-C430 radar/laser detector/jammer
Pocket PC with vent mount and GPS kit
Home-built dual 12" sub box, with completely separated 7' plywood labrynith bass ports. Rockford Fosgate Punch subs. Rockford Fosgate oldschool 4-channel amp (brought back from the dead and repaired), bridged (two channels per sub)
Sub box has been hung and wedged into place in the trunk, in such a way that the built-in Subaru toolbox and spare tire is still completely accessable without having to move the box.
Electro-luminescent lighting strips on underside of dash (this was for testing of a prototype EL controller my father and I built, and its still in and working. Can glow white, green, blue, purple, or undulate between the colors in time to the stereo's bass output)
MP3/CD player, not installed yet
ACT organic WRX clutch kit with HD pressure plate (not in yet)
ACT streetlite 13.9 lb WRX flywheel (not in yet)
Oh yeah, the VRG3 FCD! How could I forget?
Oh and the remote starter with master door lock motor (for driverside door lock - and remote unlocking / locking / arming of alarm / starting of car / turning car off)
APEXi Turbo Timer, usually set to a default of 1:30 for cooldown
VRG3's scan tool parallel connection and laptop power wired in under passenger seat / dash
Man... this is tough to remember everything. I think I got it all but hey - probably not

Interesting thread!
Edit: Forgot about the PCV rerouting with a breather on the end, no more oil in intake path - it all drips down a frame rail and eventually to the ground now, if anything.
Edit 2: Damn I'm forgetful. Had a GReddy Type S BOV, leaked at idle and was a bitch to adjust, also heard bad things about it holding decent boost levels - replaced with an HKS SSQV, guaranteed not to leak at idle or ANY boost pressure up to almost 50 psi. Sounds pretty cool, loud as a mofuggah. Gets too much attention right now, though, when my clutch is slipping and my boost is lowered. But at least it works, and works properly.