I'm pretty sure Oh! Bar is the highlight of Jackson's nightlife scene, so it deserves 5 stars in comparison to the sparse and dirty offerings around the city. On its own, though, it's just your average "party" bar, minus dancing.
They have live music from time to time, a decent bar, and is mostly standing room only. The place gets pretty crowded Friday and Saturday nights, and gets extremely loud. It's not a place I'd want to hang out for more than a couple hours, but its a good place to meet new people and get twisted for a spell.