I loved "Meld", despite the flaws that R. Star
pointed out. Yeah, Tuvok didn't need to meld with a mentally disturbed man, but his transformation into an uncontrolled, uninhibited, downright dangerous
Vulcan was fascinating to watch. I thought Tim Russ did a great job, without going overboard. Also, there's the whole holographic-Neelix-strangling scene. That probably satisfied a lot of fans.
And I've always been a fan of Brad Dourif's acting. No one does "creepy" quite like him.