I've been using this Nimbus Screen Capture for about a month, and so far it does everything I need quickly and easily. My personal favorites are the "Selected and Scroll" capture option,the ability to easily annotate what was captured, and being able to save the resulting file to my computer as well as Dropbox, Google Drive, etc.
There is only one small area for improvement - it's not clear (or wasn't to me, at least) that some annotation options are only available if you use Nimbus Note.
UPDATE: The annotation page is in fact misleading in that it lists Dropbox as a place you can save your captured file when in fact you need the Premium version. That drops my five star rating down to four.