A simple title for something so lovingly complex.
I have to say, I've fallen in love with mapping for the original Doom and Doom II. For someone who is intimidated by the Unreal Dev Editors, it's pretty simple to map in the Doom engine using DoomBuilder2. It makes it fairly easy, especially when you've mapped out the keyboard shortcuts just the way you like them.
I haven't made any real levels yet, (it takes ages.) but I've toyed around with all the fun stuff you can do that has advanced the world of Doom into the 21st century and beyond. You can practically reproduce Duke Nukem now in it, and then-some. 3D floors, swimming, slopes, fog, and the list goes on. It's brilliant.