Doom? what doom? never really took to it. As to Quake, it's really covered in Duke Nukem when there's a quake and he says 'I'm not afraid of no Quake' Pretty late on in the levels, but very funny.
Duke Nukem almost received an honorable mention in my top 5 becuase we had so much bloody fun playing that game in a lan when it came out. One of the reasons I loved it was becuase it stealed a lot of one-liners from my all time favorite movies the Evil Dead triology. But in the end it didn't make my top 5 because RPG's are better than shooters just a fact of life really.