When programming I tend to shuffle lines around a lot.

(defun move-line-down ()
  (interactive)
  (let ((col (current-column)))
    (save-excursion
      (forward-line)
      (transpose-lines 1))
    (forward-line)
    (move-to-column col)))

(defun move-line-up ()
  (interactive)
  (let ((col (current-column)))
    (save-excursion
      (forward-line)
      (transpose-lines -1))
    (move-to-column col)))

(global-set-key (kbd "<C-S-down>") 'move-line-down)
(global-set-key (kbd "<C-S-up>") 'move-line-up)

Maybe not when I program elisp, since that's sexp-based, but for other programming languages these two come in very handy. They simply move the current line one step up or down.