I'm Yours by Jason Marz
Mega hit from Jason Mraz which is always a party favourite and great fun to play!
Getting the groove to really sit nice is pretty hard, keeping the mutes strings and putting the accent on 2 and 4 and making it feel good takes practice, I feel I was getting there but not quite nailed it myself!
Make sure you check out the live performance below the lesson - it's impecable, great groove, great vocals and great performance. Backing vocal/ percussion dude is super awesome too.