I've spent a fair bit of time reading up on some of these MP3 players, and i'd have to say i think the Zen Xtra is probably the best of the bunch. If you're just looking to play music, the creative has the best sound quality out of all of them. Now, that is only if you get yourself a good set of headphones. Every single review you look for will say that the Zen has amazing sound quality, and can't be beat. When it comes to features, and ease of use, the Ipod usually wins over the competition. Plus, it's the nicest looking one out there. If you're going for overall sound quality, which i think should be something on the top of your list, go for the Zen.
When it comes down to it, do your research on them. Read up every single review you can of the product you're interested in, and then make your purchase. By now you've probably already made your choice in what you bought, but to anyone else who thinks of buying a HD MP3 player, do some research first, or you could be like a few of the guys here and bought every single one and wasted money.