I am big WWII wreck fan too! I have to say that the wrecks of North Carolina, Mooreshead City, are probably the best the US has to offer. All things considered, Long Island, NY, and NJ, are great too, (I'm from NJ), but the water is colder and darker, and the trips are longer.
For U-Boats: dive the U352 - you can get all up inside if thats your thing. Enter the front torpedo loading hatch, swim the control room, and exit the rear loading hatch. Entry to the engine room is perilious. There are still plenty of artifacts to be found on the Shurz - I find small arms ammo all the time! I found a plate last summer too.
There is sooo many wrecks there it is called the "Graveyard of the Atlanta".
For more advanced diving, check out the NJ or NY diving. The Carolina, the SanDiego, the Texas Towers, the Andrea Dorea, U859. If you need names of dive boats or outfits let me know.