I've celebrated over 300 weddings in the last 10 years and never heard vows as refreshingly honest as these:
http://www.huffingtonpost.com/lydia-netzer/10-honest-marriage-vows-you-never-weddings_b_6822620.html
While you may not want to include them officially in the ceremony (though they could certainly add some pizzazz), I'd suggest reading over them before your ceremony to get some perspective on the lifetime commitment you're planning to make.