What's the one song you can't hear without thinking of a wedding?

I've spun 'I Gotta Feeling' about four hundred times and I still get a little jolt when the opening builds — not because I like it, but because I can picture the exact chaos it causes every single time. Curious what track does that for the rest of you, and whether the memory is a good one or a 'we don't talk about that cousin' one.