Hmmm...ranking Star Trek films (original cast):
II
IV
VI
III
I
(by some distance) VI
Star Trek I was incredibly underhwhelming when I saw it in theatres and I mostly remember struggling to stay awake, though I have some fond memories because my grandfather took me. II and IV are very close for me, but II hit more in my formative years so it gets the nod. Spock's death scene was super impactful (a hero dying was a new concept for me; even though Empire Strikes Back had almost gone there, being frozen in carbonite didn't seem as permanent. Okay, both characters would be back in the next movie, but while you knew there was going to be a next movie for Star Wars, at the time it seemed like II might be it for Star Trek).
III is a solid bridging episode between them; it doesn't do a lot on it's own, but it serves its purpose effectively. V does not work for me on any level; I think Shatner is an incredibly ham-fisted director, and I say that at some risk to my Canadian citizenship (still my favourite captain, though). VI was a nice return to form, and I'm happy that the original cast went out on a positive note.
As for this new movie...Star Trek properties are so hit and miss that I am waiting for reviews before I get excited about anything. I did enjoy Homecoming and D&D:HaT, so the creative team is promising.