We had your previous question on this subject yesterday and it's pretty conclusive that even IF you can get SQL to store it's data via NAS protocols such as SMB/CIFS or NFS it's a really bad idea!
So that should discount using SMB/CIFS and NFS from the equation, let's look at the other options.
If there's no need for clustering then most people would agree that suitably well spec'ed local (Direct Attached Storage - DAS) with the right RAID level is the best both interms of performance and value.
If you are clustering then you need a block-level SAN/NAS system (you may also just want the snapshotting features some of these arrays offer too of course) - these are typically Fibre-Channel (which uses a dedicated storage-tuned network, is very fast and performance-consistent - but expensive), iSCSI (which uses standard ethernet networks, is generally slower than FC but is often 'fast enough') and the kinda-hybrid Fibre-Channel-over-Ethernet (which is a nice, but very new, compromise between FC and iSCSI).
Generally large organisations who rely on their DBs use FC and would only use iSCSI for less important work; for small organisations iSCSI can ofen provide perfectly-adequate performance for much better value (and less complexity) than FC - 5-10 years from now FC will be dead once FCoE has matured.
Hope this helps.