I noticed that you like Doom. Have you tried any of the new Doom ports (Zdoom, Doom Legacy, JDoom)? My two favorite ports are Doom Legacy and Zdoom however I heard that JDoom is supposed to get 3d floor support in the future and it already has MD2 3d models for objects and monsters so that may become my third favorite. I like Legacy the most since it has 3dfloor support as well as advanced level editing features via scripting.