Loot Rank for WoW
Loot Rank for WoW looks like another useful tool. I like this one because it lets you rank the stats that matter to you as well as specifying where loot can be obtained. Then it gives you a top-ten list of the gear that matches your preferences.
For example, hit rating matters to my hunter because she’s not hit capped. At the moment, hit rating is pretty important. Once I get 15ish more hit rating, it won’t matter anymore. My hunter may do 5 mans, but will most likely not be seeing any Kara or badge loot (let alone Black Temple loot). I can restrict my search on those criteria.
Note that using a pre-made template from the forums then tweaking it is a good way of getting some quick answers.
A Dwarf Priest has a detailed guide to using Loot Rank.