Oh god, Streets of Rage with a joystick? That would kick major arse.
I too need a joystick for my Genesis. With it, I could see what it's like to deliver a shoryuken, arcade-style.
I agree with you on Doom. In fact, I found The Ultimate Doom not to long ago for $1.25, and it plays nicely on my IBM ThinkPad under Windows 98. I am, however, having some trouble finding some good mods for Doom. X3