While there are a million configuration options out there, here are a few I'm running with:

syntax on
set background=dark
set softtabstop=2
set tabstop=4
set shiftwidth=2
set expandtab
set autoindent

Basically those options enable dark background w/ syntax and 2 space softtabs. (and 4 spaces for existing tabs).

if has("gui_running")
    colorscheme koehler
    set columns=90 lines=65
    set transparency=8
endif

For running gui (i.e. macvim) use the dark color theme 'koehler' and give some initial window dimensions. Since I'm a big fan of 80 col code, and vim really doesn't have a good way of displaying that (fail) I use a 90 col window. Also the |transparency| option is a MacVim only option for that gives the window 92% opacity.

set guifont=Monaco:h10
set guioptions=egmrLt
set enc=utf-8
hi LineNr guifg=#333333

These options are enable Monaco 10pt (aliased) and the |guioptions| passes in some flags to always open a window with the toolbar collapsed. The |hi LineNr| is to override the color themes line numbers foreground. The default for koehler is a bright yellow line number foreground, and I like my line numbers to be non-distracting.

:nmap  :set invnumber 

And finally, this option simply maps double typing control-n while in normal mode (i.e. not insert or visual mode) to show/hide line numbers. Very handy if you don't want to always see line numbers when the file opens.

Anyways, thought I'd pass on this good find.