I've put a fair amount of research into this in the past. Unfortunately, there is little to no method of creating games for someone who doesn't want to do any programming. Programming is going to be required at some point. With that in mind... Z-Game Editor - This is a very small, basic game development software package…
I think UDK would be your best bet if you stay non-commercial. If you are able to script stuff in LUA you could also try Leadwerks Engine. I use it in a commercial environment and it's like Firefox without to much abuild around it. Plus the graphics are state of the art. :) It costs 200USD.
unity is yet broken and incomplete there are to many flaws to call it even a editor. For example there is not yet a selection box (is comming though in the next version). Mac and winows version are to different (you can't write editor script panels under the mac version) and the most irritating thing is that you can't…
http://www.udk.com/licensing A bit shy of a million. I like UDK a lot as a way to make things. I am not a programmer, just a casual scripter. It's what I like, it's close to what I've used at work, so I am always learning things, and just keeping my head in it.