I"ve seen before that many people discuss about which is better and I have used both weapons.
Wunderwaffe DG-2: It has infinite damage, can kill up to 10 zombies with on shot and has 3 shots per magazine and 15 extra shots.
Thundergun: Like the Wunderwaffe it has infinite damage but it can kill up to 24 zombies with one shot(that is the maximum of zombies that appear at the same time) and has 2 shots per magazine and 12 extra shots.
The Wunderwaffe can kill up to 180 zombies if you don't waste any shots but the Thundergun can kill up to 336 zombies wich is a a lot more kills than the Wunderwaffe DG-2.
I must mention that when you upgrade the Thundergun it get 4 shots per magazine and 24 extras shots givin the Thundergun double the shots and the Wunderwaffe also gets double the shots meaning it has 6 shots per magazine and 30 extra shots, but the Wunderwaffe upgraded only kills 10 zombies per shot, unlike the World at War version in which it kills up to 24 zombies givin it the same killin potencial as the Thunder gun.
If I missed something just post it and also post wich weapon you think it's better :mrgreen: