I'd agree with the first reply (http://www.raspberrypi.org/phpBB3/viewt ... 66&t=12455
). That's what I've been using and had no problems.
I've tried the latest raspbmc and for my usage it's pretty much the same as the one above (performance wise).
I've got xbian 0.4.2 but haven't actually tried it since about 0.2. I have heard very good things about it though (I'm not just saying that because Koenkk is paying attention to this thread
). Apparently it is configured out of the box with a lot of pi specific tweaks to help playback. I'd probably say if you want something running quickly then this would be a better route than raspbmc
Koenkk - while you're here, are you able to give us a quick rundown of what is different between Xbian and a basic compiled XBMC on raspbian? I'm happy to accept that it's better, I'd just like to know a bit more about what you've done to get the best performance out of it.