A few days ago, there was bad weather along the East Coast. I took an earlier flight to LGA, instead of the usually cheaper EWR, even though I was ticketed to EWR. No fuss involved.

The LGA was eventually cancelled after sitting on the runway for over an hour (then returning to the gate, departing again and waiting on the runway for another hour). US Airways put me on a BWI flight and, because of a missed connection to a US Airways Express flight, endorsed my ticket for an American Eagle flight to JFK.