You can ask many people,who is your favorite member of the Four.Some people love Sue and hate Reed.Some others prefer Johny and his hot-tempered attitude.But what unites all the FF's fans(and marvelites in general)is their unconditioned love for Ben Grimm,the Thing.
Ben Grimm probably looks like a boring hero.He has rock looking and hard skin,super human strength and durability and that's it.It's a typical brawler and a tank.But,there are elements that put Ben Grimm into a special place in comic book pantheon.
Ben is a character who doesn't have a dark past(put aside Fraction's Doom mess) or a grim origin.Ben,while becoming a monster outside,he is,without a shadow of the doubt,a true hero.The guy will protect friends and family and the whole world with all his heart.There were times in comics,where Ben sacrificed a cure for his condition in order to help his teammates and the whole world.His kindness,his gentle rough and his selfisness,makes the Thing,one of the most classic heroes of all time.
An let's not forget his,now immortal catchphrase...