There are so many hard to get achievements it can sometimes be hard to know where to start! If possible, it would be great to go to the achievements page in the encyclopedia and by cursoring over a given achievement see via tooltip where one is on their way to achieving it. If I knew, for instance, that I was only 10 candies away from reaching the Candyglitch badge, it would let me plan better how I want to use my time. It takes a long time to brew up 1033 potions so it would be great to be able to see my progress toward that goal somehow. Etc. etc.
Have I maxed out my suggestion quota yet? ;-)