What is the best solution for letting both Macs and PCs access digital images and videos on a network?

What is the best solution for letting both Macs and PCs access digital images and videos on a network?

I'm looking for a simple way to share digital images and videos over a network to both Macs and PCs. I'm currently looking into three options: NAS, WD MyBook Mirror drives attached to a router, or an HP WHS product like the Data Vault.