Still having trouble deciding between iSCSI and Fibre Channel? Enterprise Networking Planet has a quick article that offers a balanced view of both technologies without delving too deep into the technical minutiae.
Unfortunately, the sad fact is that no single storage networking scheme is the best for every situation. iSCSI does offer impressive throughput with the advent of 10 GbE, but for truly large number crunching, you're probably better off with the large-block I/O capabilities of Fibre Channel.
iSCSI is certainly cheaper due to the fact that it rides on top of existing IP networks, but again, in environments that rely on rock-solid access to data, carrying it on the same network as e-mail and voice could lead to latency problems.
Still, for many small IT environments, this isn't likely to be a problem unless rapid growth sets in. That's why it pays to know exactly what you have now, and what you're most likely going to need in the future, before setting up your storage network.