one of the things that I really love about punk and particularly its more melodic subgenres is the fact that a huge part of the style is a focus on bass. it's usually relatively high on the mix and tends to be the most technically skilled element of most punk bands. there's so many but I'll just stick with some classics.
Rancid - Maxwell Murder; I have a general distaste for Rancid but Matt Freeman is an insaaaane bassist. pretty sure the solo towards the end of this song was one of the first things I ever heard that really made me pay attention to bass, coming from the perspective of a guitar player. it's just so stylish and groovy.
Fugazi - Repeater; Waiting Room is their most song and probably the go-to for bass discussions but among their big hitters I just can't get enough of the bass in repeater. it's like it's just one step behind the guitar and grounds the disharmonious elements of that so wonderfully. it's not very showy but it's a perfect tone-setter. fugazi are incredible in so many respects but I really admire the ways in which they blend these odd and out-of-step tones so well.
The Damned - Neat Neat Neat; don't have too much to add on this one, it's just so fun and iconic. the way it follows the vocals in the chorus is super catchy. I also like how surf rock-y it sounds, the band Agent Orange expanded on this sound really well later on.
Minutemen - The Glory of Man; minutemen songs have this wonderful stripped-down conversational element to them. I love how the rhythm section in this song holds steady while the vocals and guitar sort of swap back and forth.
Pennywise - Bro Hymn; this song has a lot of backstory to it, but essentially it was written by their original bassist about friends he had lost, shortly before he himself died. the rest of the band finished it out for the album as a tribute to him. the intro bass foreshadows the group vocals shortly after, it's really neat and has such a fullness in sound.
Dead Kennedys - Buzzbomb; DKs have a lot of great basslines that I think get kind of overshadowed because the other members of the band are insanely skilled. this one might be an unconventional pick, I'm not sure what the general consensus is on it, but it's just so perfect for the song. sounds like an engine chugging with some perfectly timed fills.
there's so many more I could mention. I should probably at the very least namedrop Descendents, Suicidal Tendencies, NOFX, nomeansno, and The Melvins even if I don't link them haha. can't really go wrong bass-wise with any of their songs.
different genre junk but I'd be extremely remiss to not bring up Primus, they're the obvious bass-fronted oddball rock stuff. hard to go for a single pick but my (extremely basic) favorites are Tommy the Cat and My Name is Mud.