I was never BIG into ska, but of the limited amount I listened to, by far my favorite Ska Album was Mighty Mighty Bosstones: Jacknife to a Swan. There's nothing SPECIAL about it, it's just got a ton of hooky, upbeat, quality ska bangers on it. My personal faves from the record are: Sugar Free, Mr. Moran, You Gotta Go, and Old School Off the Bright.

Also check out older gold finger albums, they had some solid ska tracks but were never really a ska band. Reel Big Fish and Less Than Jake are probably the most main stream bands. Ska has always been a more underground genre, you kinda gotta dig around a little bit to find the gems.