Unreal 4

Awesome. I voted for this game. The graphics are beautiful BTW.

Wake me up when game developers realize iD Tech 5 is the new engine. Hell, even iD Tech 4 would do.
I'm so fucking tired of all indie games whoring out the Unreal Engine.

Since you're not a developer, no wonder you say that. iD Tech engine is a joke, and far from the best engines around the market.

Unreal Engine is free, easy to work with and has been around for years, its toolkit also makes it easy to port the game to multiple platforms easielly.

iD Tech on the other hand, doesn't have half of the Unreal Engine features, it's proprietary (not available for third party and indie developers) and doesn't support DirectX properly, it's an OpenGL engine mostly.

The other alternative to Unreal Engine would be either Cry Engine that also has lots of features but is more demanding and harder to work with, Unity that is paid and limited/green (still under heavy development) or a custom home made engine that is expensive and time consuming.

Unity is not a real alternative if you want to make a decent game. There are exceptions though like Wasteland 2(a great game).

May I throw <span class="bold">OGRE</span> into the discussion?

No.

OGRE is a rendering engine nothing more, it's even worse than Unity in terms of features.