O Gentle Readers!

I am trying to come up with good songs to practice on my acoustic guitar. Ideally, they are the type of songs that are fun to sing along with at gatherings. Songs which require instruments other than one acoustic guitar are not something I'm too interested in pursuing right now. I have a pretty good assortment of Counting Crows, Jonathan Coulton, Blues Traveler, and They Might Be Giants picked out, so any other suggestions are mightily welcomed :-)