Automatic automatic indentation - a mode that indents code as you type.

Works pretty well for lisp out of the box.

Other modes might need some tweaking to set up:

If you trust the mode's automatic indentation completely, you can add to it's init hook:

(set (make-local-variable 'aai-indent-function)
     'aai-indent-defun)

or

(set (make-local-variable 'aai-indent-function)
     'aai-indent-forward)

depending on whether the language has small and clearly identifiable functions, that beginning-of-defun and end-of-defun can find.

If on the other hand you don't trust the mode at all, but like the cursor correction and delete-char behaviour, you can add:

(set (make-local-variable
      'aai-after-change-indentation) nil)

if the mode indents well in all but a few cases, you can change the aai-indentable-line-p-function. This is what I have in my php mode setup:

(set (make-local-variable
      'aai-indentable-line-p-function)
     (lambda ()
       (not (or (es-line-matches-p "EOD")
                (es-line-matches-p "EOT")))))