It's all about knowing what you're looking for, I stumbled upon Dark Basic a few years ago and have loved it since, it's a programming language that's quite easy to learn, but I wouldn't call it a game engine, because when I think of a game engine, I expect the game component to be together, like with Torque, Unity, 3D Game Studio etc. though DBP is designed for game creation, you use it to build up the game engine or make up the game as you go along. So it's programming central. The good think about more engines/tools is that they come with a trial and tutorials to test out.
If you're willing to program your game from the bottom, I'd recommend DBP or Dark GDK (Essentially Dark Basic in C++), Leadwerks seems fairly decent too (that can be used in C++, BlitzMax and other languages) it has a good set of tutorials on site, though it doesn't give you a demo you can program with (though you can play with their level editor for 30 days) look at the tutorials and you can see the way in which Leadwerks works.
I myself have been searching for a game engine - as much as I enjoy DBP, I like having certain jobs cut out. With game engines you'd be using editors and scripting to build your game and each engine works differently. In the time I've been looking I've tried different ones, so I'll give you my opinion on each of the ones I've tried properly (others I've not tried in depth because I've been put off by them).
Torque Game Engine: I jumped onto this one quick, heck I bought it, a few things to note: the scripting language is difficult to get the hang of, there's a lot of resources and a lot to get your started, though the manual is very in depth and it's one of those engines where you'd need to be a nice big thick book to learn from or take a course. You build everything within the game exe file and scripts, you can rebuild the game file in C++ and edit the engine, but that's more advanced stuff. It'll only import with its own file format, most of the mainstream 3D apps can export to it, and it has a free map modeller that export specifically for it (called Torque Constructor) but you kind of need to own one of the programs for other kinds of object, Milkshape is the cheap solution.
NeoAxis Engine: An engine still in development, but it has enough features to build a decent game and people already are, it comes with an editor, the scripting is done in the editor and comes with plenty of examples to use as a reference, there aren't many tutorials or much documentation. My main gripes were: .mesh import (I don't have a program that can export to this, though all you need is Milkshape 3D for this, a valuable and cheap tool to have, though I don't have it) and the editor, though the editor is good, I did not like how you navigated objects in a scene, it kind of hindered scene building.
Unity3D: the one I'm most impressed by, I'm still trying out its 30-day trial, it has many drag and drop elements and perhaps the most well though out...though drag and dropped assets will have scripts associated with them, the app already comes with a few scripts to use and the Lerpz tutorial project adds even more, but it's not too difficult to script your own. The good thing about Unity is the beginner's tutorial, which too is well thought out and quite in depth, yet practical, it steps through certain aspects of the engine and how it works by stepping you through creating your first game, called 'Lerpz Escapes' it provides all of the media you need to complete it, you just need to go through the pdf document and build it. The editor is intuitive, the scripting is not too difficult to understand, I've not found it at all difficult to pick up and it has features to save time and effort - for example you can test your game inside of the editor, it'll debug it for you there and then, you don't have to edit individual objects or scripts in the scene, you can go direct to the asset and change values. When you create variables in a script and set them up right, then they'll appear as an option in the editor, so you don't always need the scripts to set the variables. I quite like it and am contemplating purchase. It has decent support for 3D modellers, it tends to like the .fbx format, the games you make can be built for Windows, Apple Mac and Unity3D web player, so high-quality 3d games can be play through your browser. My advice is to download the trial and try it.
