Shimano SLX one of the best brakes i've used. Cheap, solid, pretty much maintence free, good power and feel.
I personally (not many will agree) like hayes disc brakes but many find them quite wooden.
Avid juicy's are decent performers but not overly reliable they have been know to leak and blow seals.
I ran a bikehut hydro for ages aswell good performance and reliable but lack feel, kinda like hitting a brick wall!
Magura louise is very good almost as good as the hope in every aspect but doesnt have that glassy-like feeling modulation of a hope brake.
But for the money i would go for the SLX every time.