There are full working games that are out there made with GE and maybe even making money. Some don't say they are GE games, some do. You're right though, it's a shame more people don't finish their games
Here's a few stright off (all have demos so you can try them)...
I am now including the latest beta I made for this project. So those who never got to play it can. There are some wierd bugs and stuff, but apart from that, it's still fun. (try and destroy all enemies without dying, it's just about impossible.)
I've started work on a new version including heaps of extra stuff, better efficiency, proper level loading, more enemies, more mission types, more secondary weapons and lots of other improvements. I will post a development log soon, so keep a look out.
Here is the old beta:
http://www.savefile.com/files/942607 Aim with the mouse, left-click to fire machine guns, right click to drop bomb. Line up with the runway fro the south to land.
I use 3dstudio max. The full version cost an arm and a leg, however, so unless you think you can make a lot of money from selling stuff made with it, it's not really worth buying it.