Not sure what to do...

Okay, so I have a Wii (shut up, I love it). A couple of days ago, I found out my friend had a Xbox 360 and got a good load of games I've been dying to play. Of course, I've always held back in buying one because I already had a game system. Now, I'm not too sure what I should do.

We don't live close to each other, so the only way to play would be to play online.

Would it be a good idea to get an Xbox as well? Or has anyone been in my situation?