Videogame-related proposals are just so damn amazing. When you have great proposal scenarios like the one from Portal 2 involving the voice actor for GLaDOS getting on board, or the amusing Claptrap from Borderlands presenting someone with the big question in his own unique way, it's easy to see why.
You might think that a game like Left 4 Dead 2 isn't fit for a proposal, I mean the zombies are scary and the game's atmosphere isn't exactly ideal to ask for someone's hand in marriage, but somehow map creator "RT Frisk" has made it happen for YouTube user EGBTMagus and his special girl.
You can tell the girl became dumbstruck at what was happening when she suspected that picking up a gnome might have been the reason why the level suddenly ripped apart. Doesn't that just make you awwwwwww?
Left 4 Dead 2 Proposal [YouTube]