[UPDATE] ShareX v12.4.0October 17, 2019
ShareX is a feature rich screenshot utility that may grab a selected area with one key and then edit, save to clipboard, drive or immediately upload them into 25+ hosting services (posts to Imgur by default). ShareX can capture screenshots with number of shapes such as rectangle, round diamond, ellipse, triangle, rectangle, polygon and freehand. Supports screenshots with shadow and transparency, as well as. Besides graphics, the program can upload drag-and-drop, in addition to other file types uploads in the clipboard, a watched folder.
Additional tools include a potent screen sound +video recorder (MP4/WEBM or animated GIF format), colour picker, ruler, FTP client, monitor evaluation, file hash checker, QR code generator+reader, picture effects and a whole lot more.