I recently switched from Vim to Emacs and org-mode was the selling point. But Emacs Lisp and M-x tetris are also good reasons I suppose.

I'm one of the people who switched from Vim to Emacs due to Org mode, and I've never regretted the decision. In the past year, I've used org-mode to take all my notes in class, write documents and as a task manager. All in all, the gain in productivity due to org-mode massively eclipses the time it took to un-learn vim and become decent at emacs.