Green. Bean. Casserole.
I only ever get it at Thanksgiving, as it's one of the "traditional" dishes we have, but I always volunteer to make it just so I can eat it! I've had a lot of people give me strange looks when I tell them how much I like it (to them, anything "casserole" = blech), but I have really grown to adore the stuff. Nothing fancy, just the recipe off the Campbell's can.
And add my vote to the asparagus crowd as well! It is one of those foods I never thought I would like, but the last several times I tried it, I loved it...always steamed so that it was still a little crunchy. I would like to make it at home but I'm afraid I might not get it right and then go back to thinking I don't like the stuff.