Here's the hardware that I can say I've personally owned:

1994: Sega Genesis (Model 2)
1997: Nintendo 64
1998: GameBoy Color (Atomic Purple)
1999: PC that could actually play games
2001: GameBoy Advance
2002: GameCube
2003: GameBoy Advance SP
2004: GameCube (Platinum)
2004: Nintendo DS
2006: Nintendo DS Lite
2006: Wii
2007: Personal Laptop (GateWay)
2009: iPhone 3
2010: DSiXL
2011: Personal Laptop (HP)
2011: 3DS
2011: iPhone 4S (Just bought it today!)

grandstand sd070
atari 2600
Commandore 64
Famicon
NES
Gameboy
Atari Lynx
Sega Game Gear
Sega Mega Drive + CD + 32x
SNES
Atari Jaguar
Playstation (3x, damn thing kept breaking...)
Sega Saturn
N64
PSone
Gameboy Color
Sega Dreamcast
Neo Geo Pocket
GBA
Playstation 2 (2x)
Gamecube
PS2slim
Xbox360
Psp
NDS
Wii
iPhone
PS3

Commodore 64 -1986
Nintendo Entertainment System - 1987
Game Boy - 1990
Super Nintendo Entertainment System - 1992
Nintendo 64 - 1997
Playstation - 1997
Game Boy Colour - 1998
Game Boy Advance - 2001
Playstation 2 - 2001
Sega Dreamcast - 2001
Nintendo GameCube - 2002
Game Boy Advance SP - 2003
Xbox - 2003
Nintendo DS - 2005
Game Boy Micro - 2006
Nintendo DS Lite - 2006
Xbox 360 - 2006
Playstation Portable - 2006
Nintendo Wii - 2006
Playstation 3 - 2007
Nintendo DSi - 2009
Nintendo DS XL - 2010
Nintendo 3DS - 2011

Consoles:
NES
SNES
Genesis
N64
PS1
Dreamcast
PS2
Gamecube
Xbox
Wii

Portables:
Gameboy
Gameboy Color
DS

NES (sold)
Amstrad CPC (sold)
Master System (sold)
SNES (sold)
Mega Drive (sold)
Game Boy (sold)
N64 (sold)
PS1 (died)
Game Boy Advance
Gamecube
PS2 (died)
Wii
DSi (sold)
PS3 (on my 2nd, 1st died)
iPod Touch

I'd get rid of the GC, but the best offer I had was to pay someone to take it off me, and I'm not kidding. I'm keeping the GBA because the screen has a scratch, so I probably wouldn't get anything for it.

Consols:
Atari 2600
Nes
Master System
Snes
Mega drive (genensis)
Sega Cd
CDi
PS1
N64
Dreamcast
PS2
Gamecube
Wii

And portable:
Greenhouse
Donkeykong
Donkeykong jr
Gameboy
Game Gear
Gameboy color
GBA
DS phat
DSi
3DS

Edit: How could i forget saturn... and i was hardcore sega fan, back in the Sega VS Nintendo days.. :)

No brackets means I still have it.

Sega Mega Drive - 1996

Sega Saturn - 1998

Playstation 1 - 1999 (I still have one, but I sold the one I got for my 4th Birthday.)

Dreamcast - 2000

Gameboy - 2001

Gameboy Colour - 2003

Playstation 2 - 2004 (He died in 2009, still have a slim though.)

Nintendo DS - 2006 (Sold at the same time as Wii, bought again in 2011)

Wii - 2007 (Sold to buy a PS3)

PS3 - 2008

PSP - 2009

Xbox 360 - 2010

Console
NES (sold first one, bought second)
SNES
N64
Gamecube
Wii
Genesis
Sega CD (sold it)
Dreamcast
Playstation (broken)
Playstation 2 (first one broke, bought second)
Playstation 3 (first one broke, bought second)

Handheld
Game Boy (broken)
Game Boy Advance (broken)
Game Boy Advance SP

Atari(I forget which)
Nes
Snes
Genesis
GameGear
Gameboy
Saturn
N64
Playstation
Gameboy Color
Playstation 2
Dreamcast
Gameboy Advance
Gameboy Advance SP
Gamecube
Playstation Portable
Playstation 3

Once I upgrade I normally give my older systems and libraries to cousins as Christmas or B-day gifts.

SNES (1992)-Siblings, later given to me
Sega Genesis/CD (1995)-Jealous of my sisters SNES, wanted my own system
Gameboy Pocket (1997)
Nintendo 64 (1997)-Genesis sucked, wanted a proper Nintendo console for a while, and finally got one
Playstation 1 (1999)-Wanted to try something new-Broke in 2001
Gameboy Colour (1999) - Everyone had one, many new games only played on GBC
Playstation 2 (2001) - PS1 broke, wanted to play Gran Turismo 3 and Twisted Metal Black-Broke in 2007
Gameboy Advance (2001) - Really in love with Nintendo handhelds at this point
Gamecube (2001) -Had an awesome list of launch games
Gameboy Advance SP (2003) - Looked really cool, was really into GBA games, reminded me of SNES days
Sega Dreamcast (2003) - Was only $99, wanted to give Sega another chance
Gameboy (2004) - Bought off a friend
Gameboy Player (2004)
NES (2004) - Bought off a friend
Nintendo DS (2005) - Got the Electric Blue one when Advance Wars came out
Xbox 360 (2007) - Gears of War "Mad World" commercial sold me, my type of games
Playstation 3 (2009) - Wanted to beat some PS2 games, and play the few PS3 exclusives which interested me-broke in early 2011
Nintendo Wii (2011) - I really wanted to play some of the Wii games, Pikmin 3 pushed me over the edge, very sad it's a Wii U title now

Soon
Nintendo 3DS (2013) - Waiting on a remake because I need a better battery, screens which don't touch, and Fire Emblem 3DS.
Playstation 4 (2014) - Want a PS4 next gen because I respect Sony as a manufacturer more then Microsoft, won't get a first gen model because of issues with PS1-3.
NextBox (2015) - Will get an arcade system if possible for exclusives. I really like Microsoft exclusives.

Also I borrow a friends PSP and PS3 now time to time.

All my Nintendo and Sega consoles still work perfectly. Only 1 N64 controller was lost to Mario Party 1. My 360 has been replace 3 times (under warrenty), got an HDMI model last year and no problems since. My PS1 and PS2 stoped reading disks at the end of their consoles generation (convienient?), but they were first gen consoles. PS3 just stopped working, but I got it used and also first gen.