PS3 - 8/10 - Impressive graphics/lighting, some solid games, but limited library and I always hated Sony's controllers.
XB360 - 9/10 - Good library, good graphics, not sold on the controller.
Wii - 9/10 - Great system, but sometimes I wish there was a better processor for lighting/shading
DS - 7/10 - Good portable system, but it doesn't keep my interest unless I'm on an airplane.
GBA - 5/10 - Good portable system, hard to see screen at times
PS2 - 9/10 - Great library, STILL didn't like Sony's controller
Gamecube - 9/10 - Great system, loved the controller, but lack of proper online support was missing
N64 - 8/10 - Great system, but my library was fairly limited due to expensive cartridges
SNES - 10/10 - Great system, great library. Good times.
NES - 10/10 - Great system for the 8 bit days, revolutionary for its time.

Wii 8/10. The consoles two biggest problems are 3rd party ignorance and bad storage capabillities

DS 9.9/10. The touchscreen scratches, other than this the console is perfect. Only reason to release a new one is so they can implement a Virtual Console-like service, only with handhelds(Game Boy, Gameboy Color, Game Boy Advance, Sega Game Gear).

snes-9/10
N64-10/10
GB/C-7/10(never really enjoyed playing on the GB)
GBA-9/10
Wii-8/10

N64: 7/10
GC: 5/10
Wii: 7/10 - already has better titles for me than N64/GC

GBC: 5/10
GBA: 3/10
DS: 2/10 - I've bought 4 titles, and they simply haven't been the quality I expect.

I'm harsh, I enjoy all of them a lot, but they all have so signiffican't ways to be improved. I always review things harshly, so watch them in comparison to each other, not rating compared to how other rate it.

I also only reviewed them from the titles I own, not the ones that are out, but I haven't bought.

I expect DS to have increased to a 5 by the end of the year.

I'll rate only the top three.

SNES 10/10
PS2 9.5/10
GC 9/10

And up to this point the console with the lowest score:
PS3 1/10 (no games for me) :(

NES 8/10
SNES 10/10
N64 8/10
PS2 9/10
GC 9/10
Wii 7/10

Im sure Wii will go higher once I find the time and money to play all of the games.

 GBC 6/10
 GBA 9/10
 DS PHAT 10/10

Gameboy: 7
wii: 7.5 (so far)
PS2: 9

NES: 8

SNES: 10 (my favorite system ever)

GENESIS: 9

N64: 8

PS1: 9

DREAMCAST: 8

PS2: 8

GAMECUBE: 7

PS3: 7 so far

Wii: 6 so far

N64: 6.5/10 - Too few games, games were WAY too expensive. Multiplayer was great, the games it did have were very good. Mario Kart MP was sooo much fun. The RAM upgrade was bullshit.

PS2: 9/10 - Just amazing, so many great games. If I counted the SNES emulator I have for my ps2 i'd give it a 10/10 as it represents the 2 best console libraries ever (snes+ps2).

PS3: 7/10 - Solid hardware, free MP, great original PSN games and media centre functionality. To up this score I need more original/unique games and budget priced games(like greatest hits). This score could go down or up depending on what happens over the next couple years.

EDIT:

GB FAT 9/10 - Just GREAT. Tetris, that mario game... Pokemon red/blue + link cable = win.

GBA 4.5/10 - The games I had were good and it was a neat little system. However, the omission of a backlight was very stupid on Nintendo's part and after fighting time after time to get good lighting, nothing seemed to work so I sold this fundmentally flawed system.