Basically there are many differnce between engines that the main diffrence is it is a 3d engine , a 3d language , 3d authoring system or an FPS?
Please specify type of engines in your database
You must know first your capabilities and your needs.
for example what languages you use ,your programming experiance,will you use shaders or not,what platforms that your game will run on so you will decide if your engine is portable or not,etc...
but the common differnces IMO are price , speed , community(this is a big one) , ease of use(has editors with scripting , just a set of libraries ,or just a RAD engine like Quest3d or 3DRad).
I use Nebula Device 2 as my Game Engine.