Most Ported Console Game Ever

[Command Prompt]

Not official, but so far its DOOM.

The following console systems have had DOOM ports.

SNES
32X
Gameboy Advance
Playstation
Saturn
Xbox
N64 (sort of)
Jaguar
Zodiac (Doom 2, and its a PDA but still counts)

And the current runner up is the Resident Evil series

Playstation
Playstation 2
Gamecube
Dreamcast
Saturn
N64