It always depends on your project.

If you want to make 2d games then TGB will be the best bet.

If you are into 3d games then it depends. Outdoor can be made very well in Torque. Best optimized indoors run in C4.

If you need the best lighting options then C4 is the best choice. Torque offers some good static shadow options just like Irrlicht.

If you wanto to do easy coding and you understand C++ well then Irrlicht is a great choice and comes with a nice editor, radiosity lighting and is very easy to use (the editor is intuitive, the documentation and C++ samples are very easy to understand). But just like Gamestudio it is not optimized to run bigger levels.

If you like easy scripting then Gamestudio is a good choice. The renderer is slow compared to other engines but for small scaled projects it can be sufficient.

If you really look for a challenge then C4 is the best option. You have to master C++ first (with all the tricks like template classes, virtual abstract classes and similar). But then you get best scene-management, optimized rendering, built-in latest shaders and good tools.

Neoaxis is very interesting. Offers tons of good features. But shadows are weak (Ogre shadows are slow). And documentation is almost zero.
But I am sure it can become a competitive product very soon.

Ogre itself is a good renderer but has no tools and does only rendering.

TGEA is still unfinished but is quite powerful. Scripting works fine there. But changing the engine code is more complicated than in other engines. It offers some good options in shadowing but is very limited if you mix meshes and blocks, static and dynamic shadows.

As you can see: Every tool has some drawbacks. I like C4 the most because it is simply the best optimized and modern one. But it is definitely not a beginners toy.