Poison spider bombshell. Mine have saved my jeep many times.
Based on that Arb should be at the top of the list with Rancho running a close second.PSC Bombshell. They are on my short list. Can't put a price on protecting such a vital piece of equipment in my opinion.
X 2. The also go on sale every so often. Best value out there.Take a look at solid axle diff covers, all under $70