Kate Mulgrew (as quoted on Wikipedia):
I grew to really love Star Trek: Voyager, and out of a cast of nine, I've made three great friends
Only three? I guess the other six cast members were all assholes, then.
I don't know if the other casts were a--holes, but I do know that Garrett Wang, Robert Beltran and Tim Russ have all stated that Mulgrew could be difficult to work with at times. Kate also had big issues with Jeri Ryan which lead to a great deal of tension on the set.
Marina Sirtis told a story at a convention I was at about how during one of her guest stints on Voyager she came for a wardrobe fitting and it was on a day Jeri and Kate were filming a scene together. Apparently, Jeri flubbed some lines and Kate lost it screaming "Do you even bother to read the f----ing script?"