UPDATE:The following is quite out of date. My up-to-date dotfiles can be found on github: https://github.com/shawncplus/dotfiles
I am not shy in the least in saying that I use Vim and that I believe it is a superior text editor once you overcome the steep learning curve. I speak for myself when I say I wear the fact that I know how to use Vim as a badge of honor. In has amazing customization options, speed, flexibility, portability (Linux, Mac, Windows, pretty much anything), power, the kitchen sink is probably in there somewhere.
I have way too many customizations to list them here in one post so at the end I'll let you download my vim configuration and mess around with it for yourself. I use gVim for most of my tasks since I do like using the mouse sometimes and one of my favorite things it can do that command-line Vim can't do is advanced color schemes. Sure, Vim supports color schemes but they are pretty ugly whereas gVim can do pretty much anyhing and it looks REALLY good. I flip-flop between a few themes to keep things fresh: Molored, Mologreen and Wombat. Molored and Mologreen are customizations I've made to the Molokai colorscheme from the Commonality blog since I'm not a big fan of pink
Vim homepage: http://www.vim.org/
My configuration