I own an xbox 360, the games available for the xbox360 (in my opinion) are the best at the moment. I wouldn't buy the Wii, because like you mentioned, after the novelty wears off the games just aren't very complicated. If PS3 was cheaper at the time I bought my xbox 360, I would have definitely bought the PS3. I owned a PS1 and loved it. I owned and xbox that was pretty cool, until the dvd rom went bad.
Before making your decision, you should check out xbox 360's reliability. I've read stories on Yahoo that say that xbox 360 failure rates are at about 30%, while Wii and PS3 are at 1%. My 360 is still going strong after a year, but if I would have seen those stats before I bought it, I think I would have paid a hundred bucks more for the PS3. Definitely do your research on reliability.
Xbox 360 technical problems - Wikipedia, the free encyclopedia