I have to agree most with C_Hoop's brief synopsis of player characteristics.
Here is my personal opinion:
Sonofabookie: probably toughest HU player i've faced, very solid all around player, his main strength is HU and short handed play. This player has good understanding and feel of situations,you have to get creative and aggressive if you want to outplay this guy.
Famousanus: very solid player, capable of making moves, and also good at reading opponents. His all around solidness is the main reason he is such a huge winner in cash games.
Mission: My nemesis

, i've battled this guy HU on numerous occasions. This player is very loose and floaty. Against this guy, the key is picking good spots to shove. This player is tough because he is not afraid to shove 200 BB with air if he feels he can get you to let go of a hand. Spewey at times.
Linecrusher: Solid player, with remarkable stats. His best game is 6 handed. Plays very clean winnable poker, def. a winner in long run.
HansenHustle: This player is very tight, don't expect him to go far post flop with air or on some tentative draw. Very hard to get this player to commit his chips. Although he won't out play you post flop, don't expect to stack this guy easily.
Machinegunian: New face on bodog. Isn't afraid to gamble and loves making hero calls, which makes him exploitable. Though his character is poor, he can be a tough opponent, depending on your style of play.
Blueflare: Very solid player, that has good understanding of table dynamics. This guy tends to play mainly the bigger games on bodog 10/20 NL and 10/20 PLO.
Foldorbebroke: Another solid player. Nothing particular stands out in my mind about him, though we've played well over 2k hands
Chumpstatus: Played this opponent alot coming up, he loves being aggressive and establishing the table bully image. Expect alot of 3-4 betting vs him. He has been on a sick downswing for some time now, i hope he can mentally regroup and get back to the higher games on bodog.
xxLisaxx: Very unorthodox player in terms of betting patterns and style of play. He has run very hot against me in the past. He is exploitable if you can pick up on betting/stylistic tendencies.
Solow: Very good player, def. can hold his own HU.
Ryan: Not sure how this guy is still playing 5/10. One of the weakest players 6 handed (never can get this guy to play HU). This player does not have good understanding of table image, situational dynamics...etc. Although, lately he has donked himself some large stacks.
XSqueezit(sp?): Yet another all around good player.
Goodjunk: Ditto, though can be spewy at times.
Pheww, didn't expect to get a list this long.