We've got a couple of pubs that keep a serious listening environment despite the tidal wave of green beer, but dozens more that really go irish for a day. It is sort of a mixed blessing, but every remotely celtic band can play party tunes almost all day on St.Pats.
Amos, last year we had Unicorn and Wild Colonial on our "if we get time to practice them" list and ... well ... we've been busy arranging the fancy tunes. ...
Donkey Riding, Drunken Sailor, Leaving of Liverpool, Isn't It Grand, Whiskey in the Jar, etc would seem to count as rousing ditties for the second gig. There's other ones we still need to run through again to make sure that someone remembers the words and chords.
What about instrumental sets; hornpipes, jigs, etc? The gb crowd usually seems sort of ambivalent if there are no lyrics.