Ok, I voted for Star Wars (But I am a huge Star Trek Fan too!)
One thing I loved about Star Wars is that the wolds look lived in, Star Trek has always been too Clean, even when they come back to earth it's pristine, what's wrong with that picture. Star Trek had always dealt with 'Ideals' and I'm not saying that's totally wrong, just that an ounce of realism goes a long way.
Another note, the Quantity vs Quality could (and probably will) be argued forever. The only thing Quantity does is give you more to remember and thus overshadows the Quality. OT: Lord of the Rings is a pristine example of Quality over Quantity.
6 Star Wars Films, 1 Great (Empire Strikes back) 2 Good (a new Hope and Return of the Jedi) and 3 'overabundant' so abundant in SFX that the FX stole from the movie. (imho)
Star Trek is a pristine example of 'Franchise gone wild' TOS was their finest hours, the Actors held up the show, TNG, DS9, Voyager, the Movies, all were second class Star Trek with ONE exception... The Wrath of Khan Movie, it was the single crowning glory to all the Star Trek Movies. But,.. they managed to make it have less meaning when they followed it with The Search For Spock. (imho) Spock's death showed his most human side and as much as I like him it was a Wrong Decision to bring him back to life. It somehow made his death meaninless.. "oooh the Star Trek main cast can even cheat death, they are gods, oooh"
Anyways, to end this rant, Star Trek has 'More' bad than good, but it came first, so anything after it will always be compared to it.
Cheers!