I develop games using the FPS Creator engine. I've used it since it's release in 2005, and while a lot of the little games I've made in it are lost on either one of my many hard drives or The Game Creator Forums, I am hoping to bring a whole new slew of games from the engine to you guys here at GameJolt.
I have also started to use the Unreal Engine 4. I hope that something great will come out of that, that I can share with you guys (unlike my poor experience with Unity3D).