Top 10 Perimeter Defenders:
1. Shane BattierOne of the most underrated defenders in all of the NBA. Everyone recognizes him as a good defender, but not as a great one. However, his perimeter is definitely tops in the league and makes him of the Top 5 overall defenders in the entire NBA. He doesn't put up good numbers at all, but that doesn't mean he doesn't play good defense. Bruce Bowen does the same thing, but with dirty tactics, however he has gotten far more credit than Battier; there's something wrong with that. If Battier can do the same (or better) as Bowen without the dirty tactics, then how doesn't he get the same respect? Regardless of how underrated he is, that doesn't change the fact he slow down some of the NBA's best players out on the perimeter better than anyone.
2. Tayshaun Prince
The long armed Prince is a monster defender on the perimeter. Like a lot of other perimeter defenders, he do
esn't put up a whole lot of good numbers (until this year), so people don't give him as much credit. He is a big part of the tough Pistons defense that has been so successful over the past few years. He usually has to cover the best perimeter scorer on the opposing team, and has done very well. He's played against Kobe, LeBron, Pierce, etc., and has had games where he slowed them down significantly. He uses his long arms and huge wingspan to block his opponents off from getting easy drives to the basket, and using those long arms to always have a hand in the shooter's face so they get no easy shots. 
3. Kobe BryantYes, Kobe can play some good defense and this is key for the Lakers. Not only does Kobe have to be the Laker's primary scorer, but he also has to be their best defender. To go along with scoring points for his team, he also has to prevent the opponent's best perimeter scorer from scoring as well. They don't put Kobe on the worst player either, he has to cover guys like Wade, Joe Johnson, etc. who are all good scorers. Kobe's incredible offense tends to overshadow his defense, but whether you notice it or not, Kobe is actually a very good defender (particularly out on the perimeter).
4. Paul PierceHe is another guy that is more known for his offense than defense, but still has some very good perimeter defense. He has gotten more recognition for this lately because of how well he played on defense against Kobe in last year's NBA Finals. It may have some to do with Kevin Garnett's influence on defense, but Pierce has always been a good perimeter defender. He knows how to keep his man in front of him, and not get beat to the basket very often.
5. Ron ArtestNow Artest is an all around good defender, and if this were based on overall defense, he might be higher. However, this is only perimeter defense and that isn't his specialty (on ball defense is). He can still play very defense well on the perimeter though. He has tons of strength and uses his big body to stay in front his man, making it very difficult to get by from points in the paint. Artest might not been seen that highly because of his bad attitude in the past, but that doesn't change the fact that he is a very good defender. You can hate him all you want, but you can't deny he has great defense.
6. Caron ButlerButler has always been a good perimeter defender, but no one knew about it until he started to become a better offensive player on the Wizards. He has the size, speed, and quickness which allow him to stay right with his man and make sure they don't get by him too easily. He is probably a better on ball defender than perimeter defender, but he still has some very good perimeter defense as well.
7. Ronnie BrewerProbably the second most underrated defender (behind Battier). Like Battier and Prince, he doesn't put up high stat numbers that get him recognition. However, he is able to keep his man from doing a lot of scoring damage. He has tons of speed and athleticism which allow him to stay in front of his man. He has become a very important role player for the Jazz, and that role is slow down the opponent's most dangerous perimeter threat. He is still young and improving, so he could very easily rise higher on this list in a few years.
8. Shawn MarionMarion, like Artest, is an all around good defender and perimeter defense is just part of his game. He is more of an on ball and help defender, but he can still play some very good perimeter defense. He is one of the most athletic players in the league and uses that to his advantage when playing defense. He may not be putting up the huge numbers he use to on the Suns, but he is still playing very good defense along side Wade which has been a big part of the Heat's success.
9. Andre Iguodala Iggy is another one of those all around good defenders. He not particularly specialized at anything yet, but he can play any kind of defense very well. He uses his speed and athleticism to stay toe-to-toe with his man and never lets them get an easy shots off. He has kind of regressed this year for the 76ers, but he is still young and will improve (probably being higher on this list in a couple years as well).
10. James PoseyOne of the best role players in the game knows how to play good defense. It's not luck that Posey has 2 rings now (from the Heat and Celtics) because he played a big part in both his team's success. Not only does he come off the bench for his 3 point shooting, but he comes in for his great perimeter defense. When they need him to, he will come in and cover the best perimeter scoring threat on the opposing team. He does very well at this, and has been huge for his team's defense and their success.
Honorable Mention (or 11th whatever suits you): Dwyane Wade He has greatly improved his defense this year and he has the numbers (team stats not just individual stats) to prove it. The reason why I didn't put him on this list is because he's more of an on ball defender. He can cover the perimeter well, but he is more of an on ball defender. He is also a good help defender too, getting lots of steals and blocks to prove that.
