What systems do you have

[ApolloBoy]

Updated my list...

[Barracuda]

Added some new systems.

Microsoft

Xbox

Nintendo

Gameboy (x2)
Gameboy Color
Gamecube (Black)
N64
NES
DS Lite (Onyx)

Sega

Genesis (Model 1 x2)
Genesis (Model 2)
32X
Game Gear

Sony

Playstation
Playstation 2

Other

Ti-99/4A
Game.com
TV Video GoGo Vision

[Tondog]

Well, I ain't updated my list...ever. So, here's the latest:

NES (Toaster)
SNES
GBA
DS Lite (Onyx)
Wii
PS1
PS2
PS3 (60 GB)
Dreamcast

[logical123]

Much needed BUMP for all the new kids on the block, and my stuff:

Nintendo:
NES - M1
SNES - M2
N64 - Gray
GameCube - Indigo
Wii - White
Game Boy Color - Kiwi
Game Boy Advance: SP - Platinum
Game Boy Micro
DS - Original
Virtual Boy 

Sega:
Master System - M1
Genesis - M1
Genesis - M1 High Def Edition
Genesis - M2
Genesis - M3
CD - M2
32X
Saturn - (Round Buttons)
Dreamcast - White
GameGear - Black

Sony:
PS - #1001
PS - #?
PSone - White
PS2 - Original Fat Model
PSP - Original Fat Model

Others:
Atari 2600 - 4 Switch Wood Grain
Atari 7800
NeoGeo Pocket Color - Weird Blue Color
Microsoft Xbox - Black

That's a total of 29 Systems. 
Not bad for a kid with no job, eh? 

UPDATED 8/15/08

[BadEnoughDude]

What the heck is a high-def edition of the Genesis? This must be a relatively new modification or something?

[logical123]

What the heck is a high-def edition of the Genesis? This must be a relatively new modification or something?

No, its just an old marketing ploy by sega. What it is is a Stereo Model 1 Genesis with an extra port on the back. And I got it for free too, with the original box. 

[Crabmaster2000]

I guess i'll add mine:

Nintendo -
NES x 2 (M1)
SNES x 2 (M2)
N64
Gamecube x 3 (Purple,Black and Platinum)
Wii
Gameboy
Gameboy color (Berry)
Virtual Boy
DS Phat
DS Lite

Sega -
Genesis x3 (M2)
Sega Cd (M1)
Saturn (Round button I think?)
Dreamcast

Sony -
Playstation x 3 (M1)
PS2 (M1)

Microsoft -
Xbox

Thats just off the top of my head but I do believe I got everything. Ill update this post if I did miss something.

[ApolloBoy]

My slightly updated list:
Atari 2600 (4 switch)
Atari 5200 (4-port)
Atari 7800 (AV modded)
Atari XEGS
Atari Lynx II
Atari Jaguar
NES (both models)
Famicom
AV Famicom
Famicom Disk System
SNES (both models)
N64 (blue)
Game Boy (original gray)
Game Boy Pocket (silver)
Game Boy Color (purple)
Game Boy Advance (white)
DS Lite (white)
Sega Master System (both American and Japanese models)
JVC X'Eye
Sega Game Gear (I have two and only one works)
Sega 32X
Sega Saturn (model 1)
Sega Dreamcast
PSX (mod chipped)
PS2 (thin)
Colecovision
NEC PC Engine Duo (region modded so it can play both American and Japanese HuCards)
SNK Neo-Geo Pocket Color
Commodore VIC-20 (AV modded)
Commodore 64

And systems I used to own:
Atari 600XL (was dead when I got it)
Atari 800XL (sold)
Atari Lynx (died)
Twin Famicom (traded for my AV Famicom)
Sega Genesis (model 1, now belongs to my brother)
Sega CD (model 1, also belongs to my brother)
Sega Nomad (sold)
Intellivision II (sold)
Odyssey 2 (belongs to my brother)
TG-16 (sold)

[Mr. Ksoft]

Home systems:
NES
Nintendo 64
Nintendo Gamecube (indigo)
Sega Genesis (model 2)
SNES
TurboGrafx-16
Wii


Handhelds:
Game Boy Pocket (red)
Game Boy Color (teal)
Game Boy Advance (original model) (indigo)
GamePark GP2X (mk2)
Nintendo DS (original model)
Sega Game Gear (Majesco re-release)
TurboExpress

[NESman93]

Xbox
NES
SNES
PS1
Game Boy
DS
DS Lite
Genesis (model 3)
Genesis (model 2)
Vader 2600
GBA SP

[ga5ket]

Atari 7800 (CIB)
Atari Jaguar

Master System II
Mege Drive 1 (CIB)
Mega Drive 2
Mega CD 2 (CIB)
Saturn oval buttons
Saturn round buttons (CIB)
Dreamcast (CIB)
Game Gear

NES Control Deck (CIB)
SNES
N64 grey
N64 Goldeneye (CIB)
Game Cube purple
Wii (CIB)
Game Boy grey
Game Boy Colour purple
Game Boy Advance purple
DS silver (original) (CIB)

Playstation original
Playstation Dual Shock (CIB)
Playstation PSOne (CIB)
Playstation 2
Playstation 3 (CIB)
PSP white (CIB)

XBox
3do Panasonic
Philips CDi
Turbografx-16 (CIB)
PC Engine white
Amiga CD32 (CIB)
Philips G7000 (CIB)
MB Vectrex

Edit: Forgot to include
Atari Lynx
Neo Geo Pocket Colour
2x Binatone Pong console type things

[Sirgin]

My modest collection:

Atari 2600 (4-switch)
Nintendo NES
Nintendo SNES
Nintendo 64
Nintendo Game Boy Color
Sega Master System
Sega Mega Drive
Sony PS2 (x2)
PC

[blcklblskt]

Here we go

Nintendo

NES (x1)
SNES (x1)
Mini SNES (x1)
N64 (x1)
GameCube (x2 Platinum w/ Digitial AV Out)

Game Boy (x1)
Game Boy Color (Dandelion Yellow) (x1)
Game Boy Pocket (Red and a Japanese Black one) (x2)
Game Boy Advance (Polar White)  (x1)
Game Boy Micro  (FamiCom edition) (x1)
Nintendo DS Lite  (x1)

Virtual Boy !!!! (x4)

Sega
Genesis - Model 1 (High Def version)  (x1)
Genesis - Model 1 (Non - High Def)  (x1)
Genesis - Model 2 (x3)
Genesis - Model 3 (x1)
Saturn (Oval buttons)  (x1)
Dreamcast (x3)

Game Gear (x2)

Thats just my stuff.  My dad has many more doubles of my systems plus a 2600, ColecoVision, etc. He might even still have his ADAM

[Atarian75]

Here we go...

1. Atari 2600
2. Atari 5200
3. Atari 7800
4. Atari Jaguar
5. Atari Jaguar CD
6. ColecoVision
7. Sega Master System
8. Sega Genesis
9. Sega CD
10. Sega 32X
11. Sega Saturn
12. Sega Dreamcast
13. Nintendo
14. Super Nintendo
15. Nintendo 64
16. Nintendo GameCube
17. Nintendo Wii
18. Nintendo DS
19. Nintendo Gameboy Advance
20. Nintendo Virtual Boy
21. Turbo Grafx
22. Turbo Grafx CD
23. Turbo Express
24. Neo Geo Pocket Color
25. R-Zone
26. Phillips CDI
27. Panasonic 3DO
28. Vectrex
29. Sony Playstation
30. Sony Playstation 2
31. Microsoft Xbox

Not counting variations, I think that is all.

-Atarian75 

[logical123]

Here we go...

1. Atari 2600
2. Atari 5200
3. Atari 7800
4. Atari Jaguar
5. Atari Jaguar CD
6. ColecoVision
7. Sega Master System
8. Sega Genesis
9. Sega CD
10. Sega 32X
11. Sega Saturn
12. Sega Dreamcast
13. Nintendo
14. Super Nintendo
15. Nintendo 64
16. Nintendo GameCube
17. Nintendo Wii
18. Nintendo DS
19. Nintendo Gameboy Advance
20. Nintendo Virtual Boy
21. Turbo Grafx
22. Turbo Grafx CD
23. Turbo Express
24. Neo Geo Pocket Color
25. R-Zone
26. Phillips CDI
27. Panasonic 3DO
28. Vectrex
29. Sony Playstation
30. Sony Playstation 2
31. Microsoft Xbox

Not counting variations, I think that is all.

-Atarian75 

LETS HEAR THOSE VARIANTS!!!