Commodore 64, NES, SNES, N64, GC, Wii (x2), Wii U, GB (x2), GBC, GBA (x2), GBA SP (x2), GB Micro, DS (x2), DS Lite (x3), DSi, DSi XL, 3DS (x3), 3DS XL, PS1, PS2 (x2), PS2 Slim, PS3, PS3 Slim, PSP (x2), Xbox, XB 360 (x2), XB 360 S, Dreamcast and N-Gage (x2).

Commodore 64 died, I was too young at the time to figure out what was wrong with it.
PS1 disc reader broke, I had to turn it upside down to get it to work and even then it wasn't guaranteed to work.
First PS2's lens reader broke and could only read certain games, the second PS2 has the same problem. The Slim still works.
PS3 kept crashing and reformatting making it impossible to get to the menu screen, when it did work some times the games wouldn't run smoothly and would stutter quite frequently.
PS3 Slim keeps freezing randomly and the wireless has stop working on it. Controllers have to be plugged into the console because they won't sync and the Wifi is unable to pick up the routers signals so it only works via an Ethernet cable.
One of the PSPs kept crashing on start up and I had to send it to Sony to get it fixed, cost £80. The other PSP still works I think.
Xbox 360 red ringed twice but it was under warranty.
One of the N-Gages just stopped working, don't know why and the other N-Gage went into the washing machine so that one was kind of my fault. XP

Edit:-

Total kill count = 

1 Commodore 64

1 PS1

2 PS2

2 PS3

1 PSP

2 XB 360

2 N-Gage

My PS1 didnt want to play games anymore I had to turn it upside down for it to keep working. (dunno what that was lol)

My PS2 phat couldnt read disks anymore

After like 15 years or so my NES has a little problem I have to insert games in a specific way for them to work (Only I know how to do it like Back to the Future's Biff Tannen in 1955 and his FORD)

My Gameboy Color's speaker somewhat broke (or the cable I dunno) I still have sound but sounds like a walkie talkie sometimes "chhhhhhhhhhhhhhhhrt"

Thats it.

Systems I owned or still own:

Commodore 64 (my stupid dad sold it)
Sega MegaDrive/Genesis
Sega Dreamcast
NES ("broke" still have it)
SNES
N64
Gamecube
Wii
WiiU
Ps1 ("broke" My sister sold it)
Ps2 ( really broke - My sister sold it)
Ps2 slim
Ps3
Ps3 slim
Xbox 360
Gameboy
Gameboy Pocket
Gameboy Color ("broke" still have it")
Gameboy Advance
Gameboy Advance SP
Gameboy Micro
Nintendo DS
Sega GameGear
PSP
Nintendo 3DS
Nintendo 3DS XL

(2) RROD 360s
(1) Original YLOD PS3 (I lost the save files for persona 3 and 4 and did not finish ether of them (almost 200 hours down the drain)) :(

Never had another system break on me.

Super Nintendo - about a decade ago still running strong when my cat decided to defecate in the cartridge slot.

Never the same after that...

NES - Needed to replace the pin connector. Was real cheap, I think $2?
PS1 - Won't read discs anymore
PS2 -Occasional Dr. Dre.
Sega Saturn - Died via loss of power
Sega Dreamcast - Controller Ports Fried
Sega GameGear - Wouldn't power on at all anymore.
XBox 360 #1 E74 Error
XBox 360 #2 RROD and after a few years disc read errors. I've had a slim with no issues since last year *knock n wood*

I had real bad luck with Sega systems lol.

I've had PC issues to but they are common.

IE Fans dieing. Power supplies dieing because of old age, etc.

If you read the back of an N64 cartridge, it specifically says



LOL

Yea, I consider your NES broken, but it died of old age, and not prematurely.

I've had several break!

• NES - About 10-ish years ago a college roommate left my NES on for days before I noticed (I wasn't around).  It hasn't been the same ever since...It works, sometimes.
• Game Boy - It still works, just that gray border around the screen is gone and sometimes I have to turn it on and off a few times to get a non-screwed up picture.
• Xbox 360 - The first one I got was dead out of the box, disc drive wouldn't eject.  Luckily had it replaced within the hour.
• Xbox 360 Dev Kit - That one was scary since it happened when I brought it home.  Luckily didn't get in trouble.  :)
• PS3 (80GB BC model) - The controller doesn't connect to it anymore without the charge cable, the controller doesn't charge, and blue tooth devices in general won't connect to it

I've dropped my phat DS so many times that there is a large dent in the corner, and the paint is worn out everywhere there is an edge, or a contact point between the two screens.

My Gameboy Pocket went through the same treatment, I even had the protective screen fall off.

A long time ago I read in an old issue of Nintendo Power two insane stories of Gameboy reliability. One guy brought his Gameboy Pocket to the Gulf War, and was bombed. I think the guy died, but the gameboy worked fine. However all the buttons were melted together, so they had to cut the buttons out, but they didn't have to open it.

Another guy dropped his gameboy colour in the backyard, and lost it for a week. They had the sprinkler on every day, and only found it when the lawn mower chewed it up. Just like your DS, it became extremely uncomfortable to hold, but the screen was all diced up, and there were sharp edges everywhere, and water stuck internally. Still worked.

Atari XE - Bad chip, replaced the chip and it still works.

Atari 7800 - Busted power button. I removed it and soldered in a replacement.

SNES - Stopped loading games. Had to replace it.

Game Gear - Sound and Video degraded - Replaced capacitors and now works like new.

PSX - Disc mount broke. Replaced it with one out of a cheap CD player. The drive motor wore and I replaced it.

Sega CD Model 1 - Fuse went out, replaced the fuse, still works. Popful Mail FTW!

PS2 - Stopped reading discs. Replaced it with a SP2 Slim

Nintendo DS Lite - Bad left should button. I haven't gotten around to fixing it because I have a 3DS XL.