I was going to post this 30 seconds ago and you beat me to it! Yes, Crimson is very good. It's basically a freeware clone of the $300+ SlickEdit. If there are any students that want a copy of SlickEdit, you used to be able to get a Student Copy for $100 from their web site.

For me, it's vim all the way. At work, I used to run SlickEdit in vi emulation mode! Once you learn to love vim, you never have to worry about walking up to a Unix box and not being able to use it. Except, well, if you have a sysadmin who is an EMACS zealot! I don't really feel the need for a full-blown IDE/Editor when writing any language except Java, where files get up in the thousands (out of control!) really quickly.