Crocodile deserves some respect here.
Rather than hold a grudge with Luffy or be petty, he accepted his loss, and honored his bargain with Luffy. Same with Baroque Works: as long as you accomplished the task, Crocodile would do right by you.
Doflamingo is willing to destroy the lives of anyone outside his immediate crew (family), and Blackbeard will fuck over ANYONE.
Crocodile can be reasoned with, Doffy and Blackbeard are total loose canons who spread chaos wherever they go. Crocodile can actually show up to a city without causing problems. He's evil as fuck, and an amazing villain, but look at it this way:
If you have to have choose between Doflaming, Blackbeard, or Crocodile to adopt a child, who are we picking? Yeah, it's Crocodile. Dude's evil, but he's not a madman who wants to start a global war like those two. He just REALLY hates the government, as seen by Cross Guild.