Take your pick from any of the following. I can probably fit 6-8 systems/games in the car easily but only 3 or 4 TVs...
Atari 2600
Atari Jaguar
Commodore 64
Commodore Amiga 600
Funtech Super A'Can (maybe - I may sell this before the event)
Microsoft XBOX
MSX
NEC PC-Engine
Nintendo 64
Nintendo NES
Nintendo SNES
Nintendo Super Famicom
Philips CD-i
Prinztronic Tournament 6 (Pong thing)
Sega Dreamcast (mine is a bit temperamental though!)
Sega Master System II
Sega Megadrive I and II
Sega Saturn - Black PAL one and a White(ish) Jap one...
Sharp Twin Famicom
SNK Neo Geo AES
Sony Playstation
Sony Playstation 2
Vectrex
Various plug and play TV games (Namco, Street Fighter II, Star Wars, C64 etc)
I also have lots of gimmicky peripherals such as Samba De Amigo maracas, Gamecube Bongos, full Rock Band setup for the PS2, Lightguns for several systems, Saturn multitaps and pads for Bomberman etc