I find that a good mix of songs/tunes goes down much better that sticking to one particular form of music when you are trying to be inclusive and get the crowd going , but for the most part stick to what you know best.
There was a time we wouldn't sing songs like 'The Town I Loved So Well' or Dirty Old Town' and The Fields Of Athenry , but if that's what they want to hear then do them .
Watch what songs get people singing and over time you get to know what they like.
I know I may get some stick for admitting this but we can go from playing Buddy Holly to Elvis and back to 'Take Me Home To Mayo' and not loose credibility [if that's the right word]