Top 10...tough and arguable but I would put these guys in the top 10:
1.) Bonds (even though he prob did steroids)
2.) A-Rod (has a lot of physical ability)
3.) Clemens (amazing what he is doing at his age)
4.) Tejada (not talked about enough)
5.) Guerrero (awesome player)
6.) Jeter (unbelievable, all around, smartest player in baseball)
7.) Santana (of the Twins, pitcher, had an amazing year last year, and going into this year doing great)
8.) Rivera (can't keep out Mariano, best closer of all time)
9.) Pujols (St. Louis, a killer hitter)
10.) Pedro (Martinez, Mets looking like the old Pedro, dominant)
It's hard to pick 10, I could come up with 10 more and argue them over these 10 but these are the ones after thinking about I came up with. I like the "overall" player who doesn't just hit a lot of home runs, but hits for average, knows the game, plays defense, and is clutch.