I do, of course, also have to deal with RAID built into Dells and Compaqs (always Adaptec).
I have used Mylex, ICP Vortex and Adaptec RAID controllers. I tend to favor Mylex (IBM) for ease of use and availability, though some of my Unix distributors prefer ICP Vortex (very similar controller).
Caen makes dynamite hot-swap RAID enclosures (with internal controllers or cabled to your controller), but being a small business specialist I don't get to use them very often.
I use IBM SCSI drives. Some time back I was building computers for a software vendor who spec'd Seagate, but I was suffering 50% failures within 2 years. Yes, I've had IBM failures, but not at that rate. Fujitsu's are supposed to be good, but I haven't used many (they dropped desktop drives but still make server drives).
Another problem with IDE RAID, by the way - every time the ATA spec changes (often) they don't work with newer drives.