This thread is tearing me apart. It's like asking for my favourite child and it feels like with which ever one I choose, they'll get shot.
I really, really want to say The Smiths because I got into them first and they totally resonate with me in terms of the beautiful poetic verses Morrissey wrote (when he wasn't a facetious Tommy Robinson bottom feeder) and the utter masterclass in sonic symphony that is the guitar work of Johnny Marr, the bass work of Andy Rourke and drum work of Mike Joyce that absolutely encapsulates something so special and idiosyncratic, you'll never see a band gel so well skill-wise (which is ironic considering the lawsuit of the 90s). I don't think you'll ever get a bassline funkier than Barbarism Begins at Home, which is saying a lot.
However, The Cure are just absolutely phenomenal. I feel considering how most forums such as Era are very much America-centric in terms of user population, The Cure will easily win because they got big stateside and The Smiths, while still well-known for being the band Morrissey was in before he went solo in America, is quite niche. The Cure however just have such incredible variety and have absolutely powerful songs in terms of structure, songwriting and lyricism. I feel The Cure are more style over substance than The Smiths but that's a dumb thing to say considering how wonderful Robert Smith is as a songwriter. I'd also say Smith has a more charismatic voice in his work that feels a bit more genuine(?)
So I'm going with The Stone Roses.