Kinda depends on what you are looking for, portable or desktop, session or on demand, ect. Personally I find a digital readout unnecessary, it's easy enough to find a temp that works for you on an analog dial, the Digi readout is just one more thing that can break.
I'm a bit biased, but I think that the e-nano is one of the best price to performance vapes on the market, but that might be because it fits how I like to smoke perfectly.
One important thing people overlook before they buy is ease of cleaning. Anything that just loads up a glass stem is gonna be WAY easier to clean than something that has an oven to load.
Have a peak at some of the threads on
FC Vaporizer Review Forum there is a lot of great info on all kinds of vapes over there. Kind of gives you an idea of what to expect.