On my first play-through,I married Lydia because I figured she'd be more useful at the house in Whiterun making money for me than she would dying in every.fricking.dungeon.....ever.
But on my second playthrough,I'm marrying Aela after she turns me into a werewolf.My plan is that one day,she will have my human/werewolf/dragon babies and after we teach them how to fight, we will spread our brand of terror across Skyrim in a campaign of blood,steel,and fur the like of which none have seen since the Oblivion Crisis in the 4th Era!........I also heard she makes a pretty good venison stew,but its mostly the blood and fur thing.