Yeah, Belle and Sebastian are rather good. I tend to prefer their earlier stuff, especially the first three EP's, they're just so... erm, corny and down-to-earth! Incidentally, there are a couple of off-shoots from B&S which you might enjoy, called Looper, and the Gentle Waves. The former is sort of electronica, and the latter is really mellow breathy girly vocals with lovely naff accompaniments. Will not appeal to everyone!
I saw B&S live at Christmas time in Belfast, and while they were OK, their support band the Frames absolutely rocked! Dunno if they're supporting still.
Andrew