Omega World pretty much supplies all the mutant, after the bomb action that I require. I read somewhere how to survive running an extended campaign of GW without growing tired of it - drop the 'players pretending not to know what mundane artifacts are' schtick. Spending two hours having the players pretend they don't know what a pop machine is, for example.
One thing that has always confused me about GW is the art. The tech level of the world when the apocalypse occurred was in OUR future, yet the art typically shows 20th century junk/artifacts. It's much easier for players to role play exploration of futuristic locales/artifacts since the players haven't used them in real life.