Had my clutch done by Outback Auto a few months ago along with a few other things. Best price I could find around, and they've gotten great reviews from everybody. I was 100% satisfied and would take my subie back without hesitation. They were helpful and very easy to work with.
I've also had good luck with PIA. Another good group of guys. I've heard mixed reviews about roopair but have friends who swear by them. They were the highest estimate with I checked on clutch though. Outback was the only place I found that was subie specific and offered flat rate pricing.