Systems currently hooked up

[Slowman]

For the LCD
PS3 Slim (2nd model)
PSP Go component cable, always plugged in/ready to go
PS4 coming soon

For the CRT
NES
SNES
PS2 Slim
PS3 Slim (1st model) - This is effectively a PS1 because that's all I use it for.

[MaterialHandlerMike]

On my big LCD:

SNES
PS3
WiiU

On my 27" CRT:

Retron 3 (blasphemy, I know)
NES

[engel762]

Currently I have hooked up;

On the LCD:
Playstation 3
XBox 360
Wii U

On the old 21" Sony Trinitron, through the use of switchbox voodoo:
NES
SNES
Game Cube
N64
Genesis/32X
Playstation
Playstation 2
XBox

[Fokakis79]

Currently Hooked up:

PS3
XBox 360
Wii
SNES
NES
Dreamcast
Sega CD
Sega Genesis
Sega 32x

[russlyman]

Currently hooked up.
Nes
Snes
GameCube
N64
Wii
Sega model 1
32X
Dreamcast
PS2
Atari 2600

[JerryGreenwood]

CRT:

NES
SMS
Genesis
SNES
Sega CD
PSX

LCD:

XBox 360

[Bear78]

LCD
PS4
Xbox 360
Ouya

CRT (Lots of switches)
Sega Genesis / CD / 32x
Sega Saturn
Sega Dreamcast
Nintendo
Super Nintendo
Nintendo 64
Nintendo GameCube / GameBoy Player
NEC Turbografx-16
NEC PC-Engine Duo R
Xbox (MAME mod)
Sony PS2
Sony PSP

LCD Monitor
Commodore 64
Atari 2600

[GamerNick]

Next Gen on my Flat Screen HDTV
Xbox 360
PS3

Retro Gen on my Flat Screen HDTV
Co-ax Cable
-NES
-Genesis CDX
RGB
-PS1/PS2

Smaller Flat Panel TV
-GameCube
-SNES
-N64

Upstairs on the 50'' Inch HD LCD TV
-Xbox 360 (Brothers)
-PS3 (Brothers)
-Wii U & Wii