Basically you can't go wrong here, I think.
My instinct would be to create either 2 or three, though you almost certainly (assuming your array has reasonable performance/number of disks) also be fine with just one.
If I went with three I'd do this:
1)for VM C: drives
2)for VM data, except for SQL (file server data, any data drive for a vm that is not just pure "utility" like a DC or such ...)
3)for SQL VM data
but really that may be over-kill (though it would not hurt you or make a management burden ...)