Last.fm has made a lot of great improvements to their site, and I have been on a good streak of finding full tracks of the songs I want to listen to. I do wish however that the player was a separate part of your browsing experience, meaning I could play a song, then navigate away from the current page (much like Beatport). I do realize there are stand-alone applications that would allow for this, I would just much prefer a strictly browser experience.
Pandora’s website on the other hand could use a major overhaul. I find it extremely difficult to navigate and clunky. I also wish they would an option to accompany the thumbs-up and thumbs-down, because I hate thumbing-down a song I actually like, but not in the context of the station I am trying to build.
Either way though, I am thankful for both sites as they have allowed me to stumble across so many great new artists/bands, and would happily live with these annoyances (and am) rather than not having either available at all.