SNES was the main
PS1 and N64 both commanded my attention equally. PS1 mostly for single player and N64 for both single and multi, but I used the former for single player games more.
PS2 was the main and the Gamecube and Dreamcast were supporting systems. Gamecube got a lot of play from me though. Smash Bros Melee alone has more hours clocked than all the games I played on PS2 combined.
PS3 (didn't need one of the other guys and definitely didn't want the other)
Next gen I intend to go with PS4 as my main and the Wii U as my supporting system. The Wii was the first (main) Nintendo console I skipped, but I'm fine with the Wii U so I'll get one later this year.
Handhelds
GB
GB pocket
GB color
DS
Vita is the main and 3DS supporting (soon)
Playstation = The Beast from the East
Sony + Nintendo = WIN! PS3 + PSV + PS4 + Wii U + 3DS