Here's a few more reasons why I'm really enjoying my Xbox 360, and have more or less stopped using my other game systems (for now). I won't repeat stuff I've already raved about earlier, except as introduction to related topics.
Xbox Rewards - Earlier I mentioned how cool achievements and gamerscores are. Well, even if Nintendo and Sony haven't figured it out yet, the Xbox team does, and they're ready to crank it up a notch. First, they're adding the possibility of connecting achievement points to downloadable content, so if you buy some extra levels for a game, they can come with extra achievements. While some people see this as a way to force people to pay more for games, I think it's a great chance to extend a game after release.
A brief digression... while I do see the danger inherent in for-pay downloads, I think the possibilities outweigh them. If a publisher develops a full game, then breaks it into a high-priced "core" and makes you pay for the rest, this can artificially inflate the price of the product. The market needs to respond negatively to such tactics. Adding extra content after the core game has been released is just cool, though. PSP's Wipeout Pure did a fantastic job of adding tons of content (for free, which is even cooler), but this hasn't really taken off on in general yet.
Back to achievements, another new innovation on Xbox is the Xbox Rewards site. This is creating meta-challenges outside the game - goals related to gamerscores in general and not just specific games. The first "challenge" is to get 1500 points in 2 months for some fairly minor prizes, and the launch was, well, horrible - saturated traffic, cranky users, the works. I'm grading this one on potential, though, and I think it's huge.
Xbox 360 Mashups - The Xbox exposes information about my last several games played through an open API, which includes what I've played, how long I've played, and what achievements or scores I've gotten. This is a totally cool thing to do, which allows other sites and projects to build without needing Microsoft's direct involvement. This is an area which is still growing, but already includes cool sites like MyGamerCard, My360Stats, and others. You can set up your own stats reports to compare your scores with your friends, and this is just the beginning. Whichs leads to my current favorite...
My Xbox 360 Blogs - Yes, that's right. My 360 has started its own blog where it encourages me, criticises me, rewards me with special badges, or just plain acts snarky. Soon I'll be able to add comments to my 360's blog, although it may be awhile before it can start reading them. For more info, there's a spiffy article on blogjects, which is way more fun word than Web 2.0
Do Sony and Nintendo have some catching up to do? Oh yeah...
BTW, if you have an Xbox, I recommend the Gamerscore blog as an interesting source of news.
Somewhere down the road, I'll need to find time to complain about my Zune, lest I be criticized of becoming a Microsoft fanboy. And don't even get me started about Vista...