I think it depends. Personally, I have a Wii, Xbox 360, and a PS3, and I like them all for different reasons.
I mostly use my Wii to browse the web, or play multi player games when friends come over. The Wii is definitely the most fun for multi-player party games.
The 360 is cool because it has some great exclusive titles, such as Dead Rising, Gears or War, and Bioshock. I would say the 360 is worth it for those 3 games alone. However, the 360 still uses DVDs, and unless they start using multi-disk games, I don't see it lasting in the long run. A dual layer dvd is about 8.5gb while a dual layer Blu Ray disc is 50gb, so it's only a matter of time before a dvd isn't enough to hold a game.
I never had a PS1 or a PS2, so that was one of the main factors to get my PS3. Plus, with the $100 price drop and Blu Ray support, it made sense to me. I have a 42" HDTV and surround sound, so Blu Ray was a natural step. Yes, the price is still pretty high, but when you compare it to the 360, it's actually a better deal. For the PS3 for $499 you get a console with next gen DVD support and wireless support and a 60gb HD. If you want the same options with the Xbox 360, you'd have to buy the console for $349, the wireless adapter for $99, and the HD DVD add-on for $179, which ends up being $627, plus, that's only for a 20gb HD. True, the selection of PS3 games is pretty lacking at the moment, but it will only get better. Plus, the PS3 is 100% backwards compatible, the Xbox 360 only supports the most popular Xbox games (but they do update every few months).
Hope that helps!