To clarify on Madmax's point... You buy a Wii. That's $250 there. Everyone keeps saying it's for multi-player enjoyment, and seems to mean the whole 'let's all hang out in one room and play mario party for six hours' kind of enjoyment. So that means extra controllers right? I assume you'd want the remote control and the nunchuck, so that's a cool $60 per extra player. Now, the Wii doesn't come with any games but Wii Sports (which is apparently pretty fun, though I haven't tried it). Let's just say you're gonna get one of the newer Wii games, say Mario Galaxy: $50. Now of course you're probably going to get aggravated and tired of using the remote only, so let's tack on an extra $20 for that classic controller. But hey, don't want it to feel like you've gone back to the SNES days? Tack on that $7 for the cool grip for said classic controller. The 512MB of internal memory probably won't satisfy your future needs for virtual console releases, media, and save games, so let's say you spend $50 on a 2GB memory stick.
So let's tally up the cost for... Well, only one additional player. Who wants to start off 4 player, right? $464 plus whatever tax you might be obliged to pay. Only $200 extra, but that's also only 1 game and 1 extra player.
Let's take a look at the Xbox360. Well actually I can't seem to find a price for just the console alone (other than the Arcade, which doesn't have a hard drive or so I hear) so we'll just go with the next closest thing. $350 for the Xbox360, 20GB harddrive, 1 controller, and two games (in this case: Forza Motorsports and Marvel: Ultimate Alliance). Say let's go for that 1 extra controller, and hell, even another game. Let's go for Halo, you can play that with your new friend/extra controller.
That will bring us up to $460 plus whatever taxes you might pay. For two fully functional controllers, a bigger harddrive, three games rather than two (not to mention I'm not even sure if Wii Sports is a 'full' game), and etc. Oh wait I forgot online crap. $510 for more crap. You get the point. They basically cost the same if you account for your tastes in accessories. Not to mention the 360 is more of a 'get one controller and play online' sort of console anyways.
On a final note, El Felixio: there is no standard for fun. To be honest, I am not a fan of most Nintendo first party games. All Mario except Mario Bros 3 bore me to tears, I've never held enough of an interest to play a Zelda game beyond two hours, and Super Metroid is the only Metroid game I've actually beaten on my own time. But sure, continue make believing that your one, narrow view is the 'right' one. It all comes down to what you like, and I don't like the Wii. Not saying it's a terrible console (the success of the thing is undeniable, people love you for creating cheaper stuff, you're loved by family people for creating a friendlier system, you rake in tons of money for how ridiculously cheap your stuff really is. It's pretty much a complete success thus far)