I've always liked "Innocence." It's a Tuvok episode that like many Tuvok episodes, tries to take him out of his element, but in the process shows us that there are a lot of elements to the character.
If you ever wanted to see a Vulcan's idea of rearing children, this is the episode for you. Stuck on an alien world, Tuvok finds himself caring for a bunch of kids inexplicably left here. They're all scared and they don't understand what's going on, and they've all heard stories about what happens to kids left here. Tuvok attempts to use logic on them. It eventually works. Pretty much.
Of course, there's a great twist to what's actually going on, but that's just icing on the cake. What other character would seem more out of place in this situation, but which one would actually handle it better? After watching "Innocence," I'll bet you'd be hard-pressed for an answer, too. Suffice it to say, he handles it better than Picard did.
franchise * series * essential * character
Memory Alpha summary.