Star Trek is the better SciFi IMO, since I don't consider Star Wars to be SciFi anyway.
SciFi is a genre that involves speculations based on current or future science or technology and how it affects people and society and generally fall within the borders of what canbe explained by science.
Star Wars is not SciFi, but is more reminiscent of fantasy.
You have funky technology (lightsabers) and space travel, but that's not what makes something SciFi.
On the other hand, you have the classical fantasy motif of good and evil (dark/light side of the force), it's champions, the good knights (Jedi), the evil knights (Sith), with their powerful swords (lightsabers), magic (the force), wizards (Yoda and other Jedi masters), rogues (Han Solo, etc.), larger than life characters, places and monsters that really have nothing to do with science, all set a long time ago in a land... ahem... galaxy... far, far away.
In fact, while SciFi usually tries to explain the technology (Star Trek explanations are notoriously convoluted, but they're still existent), Star Wars makes no efforts to explain or elaborate on the inner workings of a light saber, death star, hyperdrive, ships, machines, alien anatomy, why blasters can't shoot straight, why storm trooper armor is about as effective as a news paper, or just how the hell gungans survived natural selection.
Darth Vader doesn't care whether the planet he's about to blow up is class M or not.