A bit of an old school choice, but I've got to go with Green Day's Dookie. Not only is every song a banger, but it holds a special place in my heart as one of the first CD's I ever bought with my own money.
Great album, way to choose something even older than my pick lmao
I do have to say, though, that Milo Goes to College always struck me as more of a pure hardcore punk album and less of a pop punk album. No doubt that later Descendents stuff leans heavy in to pop punk and they were a big part of creating the subgenre in the first place (along with Buzzcocks), but I personally think that started more with I Don't Want to Grow Up
Not sure if I can pick favorites but I'd definitely rank Masked Intruder's self titled somewhere up there! Not to mention their shows are ridiculous fun.
More recently Intruder Blue did a tour over at the Punk Rock Museum, makes me wish I was closer to Vegas to go to those things.