i put an hmf on my 05 and am very satisfied...

 

LOL

 

yoshi all the way i love mine and you get to keep ythe stock heat shields so you are not buying new pants like my dumass friends with their hmf's

 

http://ctracing.com/ go there then go to raptor you'll see what i mean

 

Stick with your stock pipe until you learn more about your Raptor. Then you won't have to ask. When you ask this kind of question with no prior knowledge, you are going to get 10% fact and 90% opinion and you won't know which is which.
I had a Whitebrother R4. They quit making them. It sounded great without being too obnoxious, gave my Raptor noticable power increase and was on the low end of the pay scale for slip-on pipes.
If you can find someone that still has the R4 in stock, they are going very cheap and you won't be dissapointed.

 

Well all of the top pipes are good, We run a Yoshi on ours and love it, however I would say that you need to look at power curves for what type of riding you do, I would look into the following exhausts , Yoshimura, Curtis Sparks, LRD, LTE, & Pro Circuit. And you choose the one that best fits your needs!