Note: Questions such as 'What is the best gear for x' or 'best stats for x' get redirected here.
The best gear for your character varies on a huge number of things, and may not be the same as another person who plays the same class.
For example: whether it's a PvP or PvE fight, talents, glyphs, buffs, what gear you have access to, or even depending on how much latency you have.
Input your options to Rawr to find optimal gear, gems and enchants, customised for you. It will also give you an indication of your DPS potential.
Check the Elitistjerks.com Forums for in-depth theorycrafting for your class from experienced players.