Start with early(1963-65) Bob Marley and the Wailers stuff recorded at Studio One. Most people don't realize that Bob was a rudeboy before he was a Rasta. Bob, Bunny and Peter had shaved heads, black suits + black sunglasses + black ties...fucking gangsters!
Then check out the other Studio One artists.
I also highly recommend The Skatalites, Desmond Dekker, Toots & the Maytals and HEPCAT!!
Start from the roots and work your way up from there if inspired.
There are a lot of bands that are labeled as ska that either ARE NOT or just complete disgraces to the genre.
This is from an Amazon review and is pretty spot on in my opinion.
There are four kinds of ska:
1. Traditional aka 'first wave' (60's Jamaica) (ex. Skatalites, Desmond Dekker, Toots & The Maytals).
2. Rocksteady (late 60's Jamaican music with a tempo between the Skatalites and reggae) (ex. Phylis Dillon, Alton Ellis, Ken Booth, The Gaylads, The Paragons, Jackie Mittoo and Tommy McCook after the Skatalites broke up).
3. 'Two-Tone' aka 'second wave' (early 80's British ska revival) (ex. English Beat, Bad Manners, Madness, The Specials, Selector),
4. Neo-trad (90's traditional style) (ex. Jazz Jamaica, The Slackers, Hepcat, The Toasters, Tokyo Ska Paradise Orchestra)
Streets of Ska compilation
Foundation Ska by The Skatalites
Israelites: Best of 1963-1971 by Desmond Dekker
Best of Studio One Collection compilation
The Specials by The Specials
Out Of Nowhere and/or Scientific by Hepcat