Yeah, The Aggrolites are pretty awesome. I haven't listened to them in a while though.

Damn I forgot The Japonicas too. One of the best bands I have heard for a long while. Those and Hepcat are exactly what pure Ska is all about.

Two I hadn't seen mentioned at first glance:

The Slackers - They're my favorite! :) They're a little calmer... think Aggrolites, only with more melodies.

Bomb the Music Industry! - more ska-punk, if ska at all. Kinda silly and even a little screamy. Good horns. The good part is all of their stuff is free to download on their site.

Reel Big Fish are absolutely terrible.

I saw them live and it was like listening to a bad college radio show... they just babbled to one another in between songs and seemed oblivious that they had an audience. And then they played more terrible music.

i like Reel Big Fish AND The Aggrolites. They both put on amazing shows at Warped.

The Slackers own! Red Light, The Question, Better Late Than Never and Close My Eyes are my favorites.

However they have a couple really crappy albums (think Peculiar and Boss Harmony Sessions).

I really liked Peculiar :(

Somebody earlier mentioned that Leftover Crack might be a bit too far on the punk side. I like them a lot, but their previous band, Choking Victim, is a bit less hard so you might like them.

You should also check out Suburban Rhythm. They're really great.

I really like The Impossibles, too. They may be a bit too poppy, but I grew up on them so I'm biased.

Most people are mentioning Ska- Punk bands which is obviously popular and I like quite a few bands from those genres. Many though are far removed from what Ska is, which is a shame. This is what Ska is about: