I love karaoke and have spent years painstakingly crafting and empirically testing a list of perfect tracks. These are those tracks.
EASY (low-effort crowd pleasers):
Teenage Dirtbag by Wheatus
Cool by Gwen Stefani
Hand in my Pocket by Alanis Morissette
Torn by Natalie Imbruglia
INTERMEDIATE (either stylistically harder or easy but requires moxie):
Laid by James
I Touch Myself by the Divinyls
Cherry Bomb by the Runaways
Common People by Pulp
HARD (requires moxie and technical skill):
Hook by Blues Traveller
Semi-Charmed Life by Third Eye Blind(If you pull off Semi-Charmed Life in a public karaoke setting, you are potentially about to fuck the most bitches that anyone has ever fucked. Personal note: I can run this track start to finish without so much as GLANCING at the lyrics..)
BONUS: I'm So Tired by Fugazi. In my opinion, this is the funniest karaoke track ever. Play it really straight.