There are loads - most bars have something and most of the entertainers do the rounds. Pick up a Tipsnad Info magazine - they are free and you'll see them everywhere. Everyone advertises in there about there acts etc. It'll be a start for you.

Up at the Europa - Angelo is based at the Lepracaun or something similar (its just changed its name) apparently he's good.
Fox Allen is a good act - look out for his posters.