Ffs. Really? Frankie Edgar is probably the one fella you'd point to as having the biggest heart in the sport. Chin like granite, constant work and absolutely no quit in him under any circumstances. Never been stopped in his entire career. Not to mention hand speed, cardio, Division 1 wrestling and a BJJ black belt under Ricardo Almeida.
He held the lightweight title despite being half he size of everyone else in the division, beat BJ Penn three times, beat Sean Sherk, had one of the best fights ever with Gray Maynard, flattened Chad Mendes, beat Urijah Faber, beat Tyson Griffin, beat Cub Swanson etc.
Truly one of the greats of the sport.