[sharjeel]

MS Paint: I've yet to find a photo tool that'll load instantly and let me crop or resize with the most minimal clicks.

[Razengan]

Preview.app, the default image editor on Mac OS X, is just as convenient. I think it has fewer clicks; the selection tool is always the default, so you just drag and Cmd+K. Save-on-quit is the default as well so you just close the window.

[animeweedlord]

Really saddened that this was the lowest ranked comment, as I have an affection for classic MS Paint.

[hammock]

Photos app on your phone