Retro controllers

I’m after all sorts of recommendations and help today. I’ve got some ROMS, and I’ve just seen that Advanced Emulator Launcher was released a while back so I’m looking to have a play with that…

…can anyone recommend so decent all-round retro controllers? I don’t really want to buy one for Sega, one for NES and so on…although I like the style/feel of an Xbox controller over anything else…any recommendations greatly appreciated!