Star Wars has more entertainment value, but because of this it sacrificed substance and originality. Star Wars deals with no issues whatsoever, the only thing even remotely close being the redemption of Anakin Skywalker. Star Wars has also been done in one format or another since the dawn of time. Literally thousands of other stories are exactly like SW. These stories all involve a fatherless protagonist with some kind of special power who is guided by some sort of wiseman confront his father, eventually the mentor must die, the son must face his father one final time etc. etc. etc.
Star Trek dealt with real issues that are still relevant to the human experience. The material in the shows made you think and ask questions of yourself. That is why I prefer Trek.