Fabrik8

I'm not really sure how the power compares to the others on the market (there isn't going to be a lot of difference between 3" mandrel bent systems) but I really like the Borla stuff, sometimes listed as Borla Hush.. It's quiet and stock looking (they make single and twin tip stuff for my generation WRX). A couple of local guys have them and they're really stealthy and sound a lot better than most of the boxer exhausts out there. I'd have one on my car if I wasn't still poor from going back to school.

I can't say whether they make stuff for your 2010 though, I haven't looked. I really hate loud exhausts on boxer engines, they sound like absolute shit and amplify the not-firing-on-all-cylinders boxer sound. Unless you're talking about a Hayward and Scott system, which sounds like rally heaven.

Muncher

Not sure of they make it for the '10 but the Tanabe Medallion is a nice system as well as the Borla the Fabrik8 mentioned. Isnt super loud and looks factory (although shiny). It's (the Tanabe) is a bit pricey though.

twinturbomeow

There both a over my budget, My cousin works at subaru, said he could get the spt exhaust for around 399 with his discount. I have a lil over then 800 to spend on a exhaust but hey i could save a couple hundred so why not go with spt lol. Ill be sure to upload a sound clip for you guys to hear once it gets delivered.

but this has me convinced itll sound nice and not too loud.

http://www.youtube.com/watch?feature=player_detailpage&v=3GUT6Tjh3Jc