I'm lookin for a high quality tower defense game

[JOKA_]

Thanks everyone!

I've been playing a bunch of the ones you've recommended and I'm getting a feel for whats out there.

I'm actually asking this because I'm looking into creating my own tower defense game (Part for project/experience and also possibly to get it onto game/app stores). 

I've been googling for a while, but can anyone with an iPhone or something similar direct me to td games with good 3D graphics?  Once again I just want to see whats currently out there.