How to choose
Three questions that narrow the list
First, where does the thing you record live? If it's a web app, a tab recorder like Screenix captures it with better quality and polish. If you need desktop apps, pick a full-screen recorder such as Loom, Screenity or Awesome Screen Recorder.
Second, do you send links or files? Loom, Vidyard and Tella are built around their cloud. Screenix, Screenity and Cursorful keep recordings on your computer.
Third, how should it look? For quick messages, any recorder works. For demos people rewatch, auto zoom and a smooth cursor make the biggest difference, and only a few extensions offer both.