Thanks for all the suggestions. Completely burned out of shooting games by House of the Dead. Might look for some puzzlers next.
I've got a Wii and an Xbox (original, not one of these new-fangled 360 doo-dahs) but I'll certainly keep the suggestions for other consoles in mind.
@MrJaba, while I like the idea of buying two Xbox 360s, another TV and two copies of the game.... I think spending £500 "just" for some dual action might make the relationship might suffer more than if I continually won at Street Fighter II 😉