I'm using Emacs for about 7 or 8 years now, maybe a bit less than that, maybe more. I tried to quit several times for other editors, different workflows and everytime I returned with more enthusiasm.
It's hard to tell for those who use their editors with mouse clicks on pretty icons but once you catch this virus called doing everything from the keyboard, it becomes attached to your digital (from digitus, finger) psyche that is impossible to leave behind. I purchased an Android keyboard for my phablet just to ssh to my home and write with Emacs. Consider!
Today I stumbled upon several posts regarding favorite Emacs packages and wanted to list mine.
I'm not writing this in org-mode, because I observed that I can detail, micro-revise lose focus while writing because of the functionality in it. Instead I'm using Zsh's vared to enter lines to an org-file when I write first drafts. But editing, keeping, following, creating plots, literate programming, doing everything that can be done with text is possible in org-mode.
I have F11 bound to org-capture and F12 to org-agenda-list. F9 F9 stores links wherever I like and I can use C-c C-l in org buffers to paste them.
When I want to search google but don't like the idea to run a huge browser session just to lookup an answer in SO, then I use this.
It shows the versions created by undo/redo of a buffer in a tree format. Emacs's default undo may be cumbersome at times but this package is terrific.
To count words in a file. When I forget this package, I use C-x h M-| wc as a substitute.
Once upon a time, this mode made me to migrate from LyX to LaTeX itself.
Emacs Speaks Statistics is an R frontend. I'm not using it daily but it's much better than R command line client.
Makes buffer names unique. If you have files with identical names, this is much better than having names like myfile.txt<1>, myfile.txt<2> etc.
List of recent files.
=ido= for M-x. Standard M-x selects commands by their prefix, with smex you can filter them by any substring. This makes a difference for those with poor memory.
I use mercurial more than git and ahg-mode seems like a good alternative to standard vc- commands.
It considers directories under version control as projects and defines functions like find-file, multi-occur, recentf for them. It's very simple and non intrusive way to have project management.
For Python programming, elpy provides completion and much more functionality.
An ack mode, hybrid version of the other two.