I asked my wife to marry me on the Eiffel Tower. Big mistake. Not the proposal, but the location. Flying to Europe was costly, and surrounding ourselves with culture and Europeans for a week was a hassle and it smelled funny.
I should have done what Halo 3 player Moviesign did. He asked his girl (Furtive penguin) to enter into the bonds of holy matrimony using the Halo 3 Forge:
Awww... Nice! Moviesign invited penquin to the spot with the lure of an energy sword, but instead of the annoying weapon, she found the proposal. As you can see, the would-be groom got down on one knee, and for once, wasn't teabaggin.
She said yes.
They haven't set a wedding date yet. Because, as furtive penguin said, "We're waiting to see what the release date is for the next Halo game. We don't want any conflicts."
Xbox.com: A Halo 3 Marriage Proposal