OK, where do we start? Firstly, we can eliminate Tolkien, Martin, Rowling, Disney, Lewis, Toriyama & Tajiri. As good as their creations are, by definition I can't truly call them universes, so they're out.
That leaves Roddenberry, Lucas and Lee.
Star Trek - I enjoy it, and I think it was probably ahead of its time when the original series was forst released. The fact that new spin off series and movie remakes have been a feature of Roddenberry's creation for decades speaks volumes.
Marvel - Stan Lee's creation has probably had a bigger impact on my adult years, primarily because of the movies over the last 10 years bringing back a crapload of memories.
So that leaves Star Wars. Growing up, the Original Trilogy was huge in my formative years. To create so many iconic characters as well as launch some pretty huge acting careers. The prequels and the newer movies (despite their critics) are also quite enjoyable to watch. My 3 year old daughter already recognises C-3PO, R2D2 and Yoda, so what does that tell us about being iconic. Now if you'll excuse me, I have to get down to Mos Eisley Cantina and find a smuggler to give me a lift.