Skyrim had the ability to say to a select number of NPCs "I'm interested, marry me."
That NPC would then move into your home, cook you a meal once per day, set up a shop and give you some money from it (100g a day), and let you buy and sell items to them. The only change in their dialogue is that they now refer to you as "love" and "dear" - they don't refer to your sex in any marriage related dialogue (which means one size fits all dialogue). It isn't anywhere near the depth of Bioware's romances (even though those aren't particularly deep either, but it's like comparing a puddle to an Olympic sized swimming pool).
QFT. It just annoys me when people refer to Skyrim romances in a positive way - that monstrosity in full dwarven plate (which annihilates any gender anyway) and kept calling me "mein Schatz" (German for "my precious", greetings from Gollum), while getting lost every other minute and stomping into every single trap on the way didn't make heart fill particularly light. And I would not go as far as being called "my precious" every other second is particularly romantic. Skyrim is a gorgeous game, it didn't quite captivate me as Morrowwind, but it's still gorgeous. But certainly not for romances. IMHO they should have let them be.
Then again, to many players a romance is more a kind of achievement. It's not important how or even it actually takes place in-game, important is the step "screwed the entire crew" in the profile.