i like yevgeny kafelnikov's style generally because all his shots are fluid and always seem to be a straight line and the way he executes them also is very sort of mechanical which is cool to see. i miss him!
I love certain players playing styles for particular reasons
Federer(his balance and shot making ability)
Safin (such a fluid striker of the ball, reminscent of Kafelnikov, but less mechanical)
Ferrero(love his passing shots)
Nadal(you've got to admire his heart and his athleticism)
Gaudio(you've got to love that backhand of his so fluid, hes quite a shot maker himself)
Hewitt(love his grittiness and his never out of a point attitude)
Nalbandian( such a steady baseliner, love his two hander 2nd only to Safins)
I also agree with those who like Pavel, his baseline game is so steady and he was very good at it, at the top of his game. Arazi had a very flashy game and he was quite dangerous on clay.(his backhand was very solid and fluid)
Current Crop (in alpha order): the Bryans, Fed, Henman, Hewitt, Nadal, Santoro
Some choices are obvious; they're just fun to watch. Hewitt is included because his style is closest to my own playing style -- lots of defense but not afraid to come to net. Henman is there because that's the style I aspire to (and would explain why I was also a fan of Todd Martin and actively cheer Max Mirnyi in both singles and doubles).
On the horizon: Gasquet
On second thought, maybe Henman should go in the old timers group
Federer: Mr. Smooth so fluid and the ease with which he hits his forehand unlike most top players who muscle their FH like Andy
Gasquet: Very beautiful game, junior version of Fed
Safin: Strikes the ball so beautifully, makes the 2 handed BH look like a piece of art
Gaudio: The master :bowdown: love his backhand
Guga: Most beautiful BH ever, followed with that grunt nothing in tennis is better
Hewitt: Sheer tenacity and fight, very admirable
Nadal: Lefty, I love lefties, I just find it very amazing the way they strike the ball and serve with so much spin.