I don't think that there is a general answer to this. It always depends on what you plan to do with your storage. Whithout knowing that any suggestion would be a complete guess.

And I think that's why there ha sno answer posted to this question yet.

We are setting up mainly file server storage, that is presented as iSCSI volumes. My RAIDs are almost always external Infortrend RAIDs with 16 drives in a RAID6 configuration.
But when I am setting up storage for our Oracle Database cluster, I tend to go with RAID10 instead, because in this setup favor less latency over higher bulk throughput.

Cheers,
budy