http://en.wikipedia.org/wiki/Standard_RAID_levels
Running just the disks as standalones and doing regular backups might be your best bet.
It sounds like you have too much storage for RAID 1 to be reasonable because it's too inefficient.
RAID 5 is popular, but, there is some concern about recovering from a disk failures now that disks are so big. As your odds of bad sectors among big disks is reasonably high. Data density has increased a lot in the past few years, but, the number of bad sectors/GB(or sectors that will fail over the life of a drive) hasn't really gone down a whole lot.
The 'cool' setup is what a friend of mine did, and likely what I will copy when I get around to making an actual file server. He runs a dedicated RAID controller that takes up a PCI slot with (I think) 10 2TB disks connected running a RAID 6 setup. Its really fast and can recover from multiple drive failures. It's probably somewhat excessive for home use. We had a couple of gigabit LANs setup with ~30 users in the barracks that pulled from it for streaming movies and such.
I don't/haven't worked in a datacenter or anything just what I've delt with for some of the government systems I've supported in the past where people would(did) get
really angry if the data was lost.