The only one I enjoy re-watching is Generations. I'm a Malcolm McDowell fan and enjoy his portrayl of Soran. Its also the first ST movie I went to see in the theater by myself, so it has a bit of a special place in my heart to me.
Worst for me, First Contact. Special effects were pretty bad, the story was hokey, the way the characters acted (especially those on Earth) seemed fake and annoying, and Cochrane was just too annoying for me as well. Also, I find it very hard to believe that Geordi and Riker were both part of the warp flight. Just seemed too cheesy for me.