Unreal Engine is by far the most powerful engine in gaming, and has been for over a decade.
Unreal tournament 2004 looks better than any xbox 360 or ps3 game out TODAY and that game came out in 2003.
Unreal Engine > Quake Engine > Crytek Engine
it used to be KIND of close between unreal engine and quake engine, but now I feel its not close at all.
People talk about how good looking Crysis is, have no idea...
edit: As much as id like for them to make a Unreal Tournament 2014, theres no point.. people dont like challenging games in this era. Actually people never really liked challenging games in any era which is why counter strike, one of the most basic

fps of all time, was way more popular than Quake and Unreal Tournament. So just keep making them engines, I know thats where they make their real money at anyway