What's a good 'exercise' (please see details)?

Okay, I’m not looking for something expensive or hard to do.

Ideally, I could do it at home.

It should also be fun.

I’m not looking for something to lose weight so much as to be in better shape.

I’ve tried yoga before—does this actually work as a way to stay in shape? (I realise there’s power yoga/flow yoga out there, I’m talking more about hatha (?) yoga.) Also, when I tried yoga before, it didn’t really seem ‘fun’. (The reason why I want something fun is so that I’ll have a better chance to stick with it/want to do it in my free time.)

Thanks for any and all ideas!