There are few items I would replicate, mostily choice guitars I've seen in music videos. What would you replicate?
Assuming I was on Voyager, I'd replicate Voyager. Actually, that's probably how they made the ship regenerate a la Bugs Bunny.
Problem: If you were IN Voyager when using the replicator, you'd have to replicate a slightly smaller Voyager, so it would fit inside. You could make Voyager nesting dolls.
At the moment, I'd replicate myself a new wardrobe. I cleaned out my closet and could use some new stuff, but clothes aren't cheap. I've been watching sales and grabbing things here and there as the deals come along.