I got into punk more out of curiousity (to get a better historical perspective on the late 70's musically), rather than having liked what I heard. But there are some bands I really came to enjoy. I love the first 5 Ramones albums (with Road to Ruin as my favourite), great rock 'n' roll. Play their self-titled back to back with Little Richard's debut and you'll find the same type of energy, excitement and fun. The Clash are great too. Not too many bands can start out as punk then go in a million directions without losing the spirit. The Sex Pistols record is pretty entertaining, if not memorable throughout. Steve Jones is the true star of the record, not Johnny Rotten IMO (or God forbid, Sid Vicious, who doesn't even play on it). NOFX are good too, I love bands who don't take themselves seriously. Haven't heard much Green Day, but Basket Case is a classic (then again, they also have that song with the "I hope you had the time of your life" part, ugh).