bash
The GNU Bourne-Again SHell (bash) is my shell of choice.
So I’ve almost got my .bashrc as cool as my .cshrc was. Until recently, bash was missing programmed completion — and it was driving me insane. Of course I haven’t done a darn thing with this capability since it was added, so maybe I was just insane anyway.
I had gone so far as to hack the bash installed on NERSP to do MH folder completion, which got me 80% of the way to not angry.