If compactness is important, and you are comfortable with the on screen keyboard, then you probably want to avoid the cases with built in bluetooth keyboards. They will add size and wieght (to a dgree) and certainly cost.Beyond that, you will have to make some decisions about what you need the case to do.
For example, when I picked up the case I am currently using for my new iPad, I wanted low cost (I'm rough on them so will need to replace at some point), decent padding to protect from bumps and such, and to be able to easily get it out of the case since I like using the ipad without a case when I feel it is safe. The smart cover feature was not a concern since i find that peice of functionality to be a waste of time. I ended up with a Rocket Fish. Simple design, meets my needs and i don't have much invested, so easy enough to replace if I run accross something a lot better. (also, this was early on and there weren't a lot of cases in the stores yet). Obviously, from the information provided, that case wouldn't be to your liking.
If you have the ability to, go and actually look at and hold some cases. very often that tells you more about how well the case would work than reccomendations and reveiws. and make sure you are clear on what you need the case to do.
For out and out protection, however, you probably can't do much better than Otterbox. My company has deployed iPads on construction sites and chose the Otterbox Defender as the REQUIRED case for all iPad orders.
