Atari 2600
Nintendo Entertainment System (NES)
Nintendo Super NES (SNES)
Nintendo Game Boy (Original core with no Tetris, during promotion when Zelda was included)
Nintendo Entertainment System (NES, model 2, top-loading)
Texas Instruments TI-BASIC (not sure if this was the actualy model name)
Nintendo Super Game Boy (adapter for GB games on SNES, does this count?)
Nintendo Game Boy Pocket (Silver)
Nintendo Game Boy Pocket (Clear)
Nintendo 64
Atari Jaguar (new for dirt cheap, promptly sold it)
Acer PC (IBM/Cyrix "P150" CPU, true Mhz unknown, doesn't count, but listed for time reference)
Nintendo Game Boy Color (Atomic Purple)
Nintendo Virtual Boy (Brand new and dirt cheap, so much fun!)
New custom PC (Pentium III, doesn't count, but listed for time reference)
Nintendo SNES (smaller model-2)
[various Compaq laptops throughout remaining, endless problems/replacements for years]
[various custom-built PC systems over the remaining years]
Nintendo Game Boy Advance (Japan import, later stolen and re-acquired)
Nintendo Gamecube (stolen)
Nintendo Game Boy Advance (Platinum)
Microsoft XBOX (destroyed shortly therafter)
Nintendo Super Famicom
Sega Genesis (multiple variations)
Sega 32x
Sega CD
Sega Powerbase Converter
Philips CD-i (with the two "turd" Zelda games)
Nintendo Game Boy Advance SP (Cobalt Blue)
Nintendo Game Boy Advance SP (Limited Lime Green)
Sega Dreamcast
Nintendo Game Boy Advance SP (Classic NES Edition)
Nintendo Game Boy Advance SP (Limited Pearl)
Nintendo Game Boy Player (GBA adapter for Game Cube, does it count?)
Datel Advance Game Port (GBA adapter for Game Cube, multiple hardware/software versions, does it count?)
Sony PSone (smaller, with LCD, later stolen and re-purchased)
Sega Game Gear (never worked)
Sega Master System
Nintendo DS (x2, "phat")
Sony PSP
Microsoft XBOX 360 (purchased and sold new)
Nintendo DS (special color with free exclusive Nintendogs Best Friends Edition)
Acer laptop (dual-core Intel top-o-the-line specs...I know, it doesn't count)
Game Boy Micro
NEC Turbo Express
Nintendo DS Lite (x2)
Panasonic R.E.A.L 3DO
Too many details, variations, repurchases, to list. Probably missed some platforms too.
[edit]
Aw, man. After looking through this thread, I'm too embarrassed to add anything else to this list if I do remember.
Nearly all of these I still have. No matter how strange it looks, the order that I obtained these is still roughly correct.
I'll purchase the following when I see a kick-ass deal for brand new merchandise:
Sony PS2
Microsoft XBOX
Microsoft XBOX 360
WILL OWN VERY SOON:
Wii
Perhaps 5 years from now, give or take a few:
PS3