Ivey and it's not even close - which is not to take anything away from Hellmuth. He's even worked on his mixed games in recent years, he gets a lot of flak but I think he's actually a pretty underrated player.
But the only reason Hellmuth has more bracelets than Ivey is because he plays more tournaments and has been doing so for more years.
Even if Hellmuth is the best, I'd still vote for just about anyone else to be better. I know he's got a track record of winning, but I can't stand the guy. Can't stand whiners in general.