Old TV Converted into Seinfeld Fish Tank

The finished Seinfeld fish tank

complete with furniture, backdrop and Jerry, George, Kramer, Elaine and yes...even Newman.

Old CRT TV

First you need an old cathode ray tube TV.  The bigger the better.  I found one on Craigslist for about $30.
Removing the guts of the TV

You need to CAREFULLY remove the internal components.  This can be extremely dangerous as the capacitor inside could still hold a large charge.  If in doubt, there are some great instructables online.  I also have some links on my website for how to do this safely.
Success

Now that the screen and guts are gone, we have a nice little aquarium stand and frame.
All cleaned up

The completed TV

Installing the aquarium

Making the backdrop

I got a sweet image of the Seinfeld living room from a programmer who made a VR model for Occulus Rift.  I had him remove all the furniture for me and then broke it into 3 images in photoshop.  I added a forced perspective to the sides to make the whole thing look right.  Next, I got the images printed at size and laminated and added them inside the tank.  Placing them on the outside gave a glare.
Filled with water

I got some gravel, fish and 20 gallons of water and this is what it looks like
Finishing touches

I have been procuring authentic looking 1:12 scale doll house furniture off Ebay and even made some pieces myself out of modeling clay.  I also got a tiny aquatic plant and a tiny pot for the corner.  It turned out pretty awesome.  The fish seem happy, although I bet they are pretty confused.