So what exactly is this list based on? How often you see these players on TV? Seems pretty poor basis for rating these players. LOL @ Jennifer Harman being awful.
As someone that has played with many of the top professionals and with friends that have played against all of them, I'm going to go ahead and say this list is plain wrong.
Daniel Negreanu: very good but not top 10. Is a bit of a calling station from my experience, but I've seen him make a few good laydowns.
Phil Ivey: easily top 5 as any pro will tell you, probably top 3
Phil Hellmuth: uhh have you watched highstakes poker? Hellmuth is awful. He is good at playing against people with no clue in tournaments, in cash games he is clueless, and against good players he is easily exploited. He is good and has been successful because he excels at beating large fields filled with weak players, such as found in the WSOP.
Doyle Brunson: very good but not top 10. Probably lacks the stamina to compete in big tourneys but still has the mental prowess to beat the highest cash games.
Johnny Chan: good tournament player but no longer has the patience to outlast large field modern tourneys
Gus Hansen: A pioneer of many loose aggressive methods, but has not truly mastered them. A very strong, maybe top 25 but probably at the bottom of that list.
Chip Reese: Good at cash games, consistent winner at mixed games which is why he excels at HORSE. If you put him up against top internet players that specialize in one game he would get creamed, but I still think he is top 5 all-around just for his versatility.
Allen Cunningham: top 5 large
J.C. Tran: Never played w/ him, don't know much about him.
Barry Greenstein: Very good, especially at handreading. Very tough to fool. Excels at playing the shortstack and also a very nice person.
Chris Ferguson: Good at tournaments but limited experience in cash games
Mike Matusow : Ugh why is he on the list? He's not good. He tilts easily, he has no bankroll management, he's in debt up to his eyes, and his poker game frankly isn't that good. I know many many amateurs that are far better than this joke.
13. Phil Laak Not good, doesn't deserve to be on the list
14. T. J. Cloutier Another degenerate, gambles all his poker winnings away on craps. Deep in debt. A competent tourney player but I wouldn't put him on the list.
15. Antonio Esfandiari Never played with him, from what I've seen he seems pretty good, top 50
16. Jennifer Harman: Top 10, Top 5 in Limit Hold'em. Amazing player.
17. Erick Lindgren: Good tournament player, easily top 25
18. Michael Mizrachi: Meh. Decent but nothing amazing. Another pure tournament player.
19. Paul Wasicka: Never played with him, not too fond of his Open ended straight flush laydown at the final table of the world series of poker, but I think he has a good head on his shoulders and could beat high stakes poker.
20. Scotty Nguyen: never played with him, no opinion
21. Howard Lederer: Can't make up my mind on this one. He's a genuinely nice person, but his game is too solid and he passes up too many edges to be a top player at NL, I think. He's also a top-notch limit hold'em player.
22. Erik Seidel: underrated tourney player, hasn't done much recently for some reason, never played w/ him
23. John Juanda: top notch NLHE tourney player
24. Greg Raymer: has a typical internet hyperaggressive style that he plays quite well. Not a top poker player, I hear that he's pretty good at omaha but in NLHE he's mostly a tournament player. He's quite good at using aggressive bluffs, semibluffs, etc. to force people to a decision for all their chips, and often they just fold rather than risk a coinflip. Very effective style, but it's also quite risky.
25. Sam Farha: Loose and aggressive, but he's nothing special at hold'em. He's competent at tournaments but his true strength is in pot limit omaha, where he's among the top 3 players in the world.
26. Men Nguyen: never played with him but I'm not to impressed from what I've seen on TV
27. Eli Elezra: Very good shorthanded cash game player but lost when it comes to tournaments or 9handed play.
28. Humberto Brennes: This has got to be a joke, right? This guy only plays AA, KK, AK. He's a complete nit and really isn't any good at all.
29. Todd Brunson: Never played with him, I hear his style is similar to that of his father's but I don't think he's as good a player as his Dad.
30. Annie Duke: ANother joke. Annie Duke is not even close to a top player.
The fact that names such as Brian Townsend, Patrik Antonius, David Benyamine, Brad Booth, and Phil Galfond were ommitted say to me that the original poster basically just watched the World Series and WPT on tv and made a list of faces he remembers without any true analysis of the games.
Brian Townsend and Patrik Antonius are better at No Limit Hold'em than anyone mentioned on any list here, save for possibly Phil Ivey, and there it's close. Benyamine is better at Omaha than anyone listed.
Also, there are a ton of top internet tourney professionals that put most of this list to shame. Shane "Shaniac" Schegler, Adam Junglen, Eric "rizen" Lynch, Darryl "gigabet" Dicken, (Greg "fossilman" Raymer), Jimmy "gobboboy" Fricke, Jordan "imsolucky0" Morgan, and Jason "Strassa2" Strasser have all successfully jumped from online tourneys to live tourneys and are having huge success on the tourney circuit, winning millions every year.