If you talk to the main character, the things goes like this, man.
Canonic Vault Dweller > Courier Six > Chosen One > Lone Wanderer >>>> Sole Survivor.
Of companions, i would say Charon of Fallout 3 or Craig Boone. Both were hard as fuck.
Else, Frank Horrigan or Ulysses. So, Frank survives the FEV tests and then he is suited up in a gigantic Enclave Power Armor. Is anything as badass as that?
Ulysses walked the Divide, the hardest DLC i have see. He has a hard son of a bitch, and that voice made him even more badass. He can be as great as the Courier, but he was in fact the original Courier Six. And that is pretty badass.