I have two beefs with Star Trek
-The relationships in Trek suck. They are so forced, and not very well written. Even the Odo/Kira one had some issues, even though it was the best one. No scifi series can do a relationship like the one Crichton and Ayren had in Farscape.
-They don't do death very well. Spock's was good, Sarek's was the best, but Yar and Dax should have gotten better deaths.