I've only used PiTiVi and OpenShot.OpenShot is reliable, but doesn't have a lot of features. It's kind of comparable to Windows Movie Maker.
PiTiVi is much more powerful, but I've had trouble with exporting the videos; it seems a lot of formats supposed to be available just don't work.
I've heard that Cinelerra is pretty good, but I haven't tried it.
