I'm into sci-fi shows and bought I would post a few of my favorite shows here. You don't have to post sci-fi, post anything you like!
Fringe - very cool parellel universe show
Doctor Who - classic time traveler
The Lost Room - show about a key that opens any door to a room. Items from the room are indestructible and help/hinder the main character rescue his daughter who got stuck in the room.
Parallels (a 2hour tester show) - a building activates every 24 hours and travels to alternate Earths. Some kids are following a trail left by their father.