My first three that I can recall were:
Enema of the State by blink-182
A Hangover You Don't Deserve by Bowling For Soup
Mmhmm by Relient K
but a big shoutout to Milo Goes To College by the Descendents for being the first traditional punk album I ever really got into.
I was a massive KISS fan in 1977, and around 1978 I got into Ska along with my buddy Paul. That summer, Paul went to England with his parents and brought me back a bunch of albums, like the Sex Pistols, Never Mind the Bullocks, and the Clash, "The Clash". But it was Black Flag's, "Nervous Breakdown" that got me fully into the punk scene here in Los Angeles.
I'm still active in the scene, and still see shows.