So, I've recently started playing Phantom Dust for the original Xbox (which, admittedly, I've had lying around for months) and I can't even believe how awesome it is.
The absolute best part of Phantom Dust, however, is the fact that it supports Xbox Live. You can hit the internets with your custom-built arsenal and take on your friends (one on one, two on two, free for all.....there's even local splitscreen!) or you can place your spare skills (yes, you can get doubles) on the auction block and trade them with others. The coolest part (I think) about playing online? There are something like 74 ultra-rare skills that can only be attained by playing online. For every 30 matches you win, you're awarded one of these skills at random. This makes it a little difficult to collect each of them, but hey, at least you can trade. :D
Sadly, the game is pretty old now (it hit the original Xbox in 2005) and didn't sell too well from the start, so the online community isn't exactly booming these days. The good news about it being so old is that you can buy the game used for nearly nothing (It was $20 new when it came out, so you can imagine how cheap it is used now). It's backwards compatible on the Xbox 360 (which is likely the selling point for most of you) with pretty good emulation, aside from a little slowdown when the environment starts taking a serious beating from all the skills being thrown around.
Anyway, the main point I've been trying to make is this: Phantom Dust is amazing and I think anyone who doesn't hate fun should play it. I also think anyone who plays it should let me know, so we can get an awesome little group together and have some fun online. I would love to take you all on and try to rack up enough wins to get those ultra-rare skills while I'm at it. It'd also be nice to be able to trade each other and such.
I highly recommend Phantom Dust to all of you, so go out and buy it, right now!