Old thread but I couldn't post back then so I'm bumping it.
Martin easily but Fresh Prince is still good. It's 2 different lanes though......raw situational comedy verses a more serialized family sitcom. It's like comparing Sanford & Son to the Cosby Show.
I think, comedy wise, Martin was much more influential in Black comedy and the show holds up better overall when it comes to jokes, gags, iconic moments, guest appearances, and its roster of characters from the main cast to Bruh Man, Hustle Man, Reverend Leon, etc. There's just so many classic episodes and scenes like the one where Gina first found out Tommy and Pam were dating that just blow even the funniest scenes on Fresh Prince out of the water. But Fresh Prince was still pretty funny for a family friendly show. Will and Geoffrey were the funniest while Carlton and Hillary have a more gimmicky style comedy that's a bit more forced but still produced funny moments nonetheless. But there's just no comparison at all.
Fresh Prince technically does have a better and more developed storyline across the seasons with more deep moments with social commentary and life issues but I feel Martin did more with less. It wasn't that story driven or deep but it made up for it in comedy, a strong character ensemble, and relatable plots that showed working class Black people in a non-street/hood light.
Martin is a spiritual successor to Sanford and Son and In Living Color while Fresh Prince was a spiritual successor to the Cosby Show and Different Strokes.