not all of them are really 'Irish' rather more Celtic in general, but some bands worth checking out:
flatfoot 56(great band)
the mahones(another good one)
mainstreet saints
the Tossers
McGillicuddy's
Morgan knockers
Mr.Irish Bastard
Neck(great band)
The Real Mckenzies
Street dogs(old lead singer of Dropkick murphys, not exactly Celtic but has the feel)
as for some more 'tradition' Irish music u can check out a few of my favorites:
the dubliners
the pogues
Irish decedents
check out The Dreadnoughts. *thumbs up* they're not very big yet but they're absolutely fantastic. they put on an amazing show!! super nice guys too :P
i was there :D lmao. i'm actually good friends with the whole band. help out with their merch sometimes and i usually stay with them when they're in toronto but i couldn't thursday.
i was there. didn't have my hawk up though :P
ummm i was the blonde chick sitting at the merch table during the brains and the koffin kats. and i was the one right at the front when the dreadnoughts were on. ^___^