I'm not of much help, to say the truth mine looked good and was a pro hair dryer from Babyliss i found on discount. But i've had it for a couple years and it works so well i don't regret it.
Try to look for two heat settings and speeds, if possible also a cool air button (it helps setting your hair and feels really good on your scalp). Two different nozzles to diffuse the heat according to your style. If you can get a ceramic one, that's good. Most of the hair dryers now use ionic technology to prevent stastic, which can be good to have as well (the two can be combined).
A real bonus would be something to store the hairdryer or at least the cord.
It also should feel comfy in your hand, not heavy, and you should have an easy access to the buttons to change the setting.
Also, do you plan on keeping it in your bathroom, or travelling with it ? This also has an impact on the size you should buy.