I was in the same situation as you last month!
I would recommend getting Wii console, Wii fit (with fitness board) and a second controller (which can be bought with Wii Play)
You can get a bundle here click here(with%20fitness%20Board)&platform=WII
Reasonable price but I don't know if you can get it cheaper elsewhere.
Both the console and the board come with games discs.
Extra controller with Play - click here
Great fun for all the family to play with (kids to grand parents). What I really like is it gets people playing together (unlike other games which tend to be solitary)