What sort of music you into???
Anything really, although probably not stuff that's too heavy.
Last time I went was 2007 and acts that I remember as being pretty good to watch then were silversun pickups, subways, seasick steve, bloc party, plus so many more

Looking at the list this year so far I think I'm looking forward to seeing mad caddies, florence and the machine, blackout, plus most of the big-ish bands.
More interested though in finding decent acts on the smaller stage, what was the carling stage in 2007 was really good as it was a pretty small venue.