It's amazing how choosing the right keybinding for a feature can change your opinion of that feature. I've thought Expand-Region was neat for a long time, and it has been in my configuration at various points, but I've never used it on a regular basis, until now. 

(use-package expand-region
  :ensure t
  :pin melpa-stable
  :bind
  ("C-<prior>" . er/expand-region)
  ("C-<next>" . er/contract-region))

On both my laptop keyboard and my Kinesis Advantage, the Page Up and Page Down keys are very accessible. At the time of me writing this, I have used er/expand-region over 400 times in the last two weeks, which I'd estimate is an order of magnitude more than the entire time before that.

Here's the great Emacs Rocks video demonstrating Expand-Region.