Roshi for me. He's a fan favourite among all the Dragon Ball communities I know of, for example he was consistently the most requested DLC character in FighterZ according to fanpolls, but I never really liked him. Jackie Chun on the other, was an absolute lad. Seriously though, he had some great moments in early Dragon Ball like with Nam for example but those moments don't really happen anymore and he just has the pervert stuff except unlike Dragon Ball which would often comedically punish him (like when Honey I Shrunked Myself to spy on Bulma in the bathroom and ended up getting flushed in the toilet or when he refused to train Goku unless he got him a hot babe and he got stuck with Launch's insanity) Super doesn't even bother so he just lost a layer of his comedic schtick and is just left with the one note.
Him getting a spot in the Tournament of Power and being more useful than guys like Krillin and Tien bothered me too. Like, when Tien is introduced Roshi acknowledges Tien would've beaten him And I think he outright states during the 23rd World Tournament that they've all surpassed him so there was no reason to enter. And it's not like we ever see Roshi training in-between all that time, he has no reason to. I know it's fun to dunk on Yamcha because he's Yamcha he exists to be dunked on but like, Yamcha should logically be stronger than Roshi. I mean, I do appreciate them giving more time to other characters, but it was a pretty hard sell for me to accept his role there. Though to be fair, in both the anime and manga versions, most of the other universes combatants felt like fodder.