I know it will never happen but this would make for a cool tower.
Tower Name: The Lab
Type: barrack/unit-based
Upgrades include
name: Gamma radiation
quotes: "Don't make me angry. You wouldn't like me when I'm angry", " HULK SMASH"
description: Units transform into lumbering gamma-irradiated hulks of the green variety
name: New Prometheus (Mary Shelley's original title for Frankenstein)
quote:"It's Alive!!"
description: Deceased units are reanimated using Victorian-era science (complete with electric diodes protruding from their necks);
name: Mult-Million Dollar men
quote:"Gentlemen, we can rebuild them. We have the technology.", "Hasta La Vista, Baby",
description: Physically impaired units are bionically/cybernectically enhanced, getting a chance to deliver some serious payback
Any other crazy tower concepts out there...