I am hooked on McDonald's McNugget sauces. A torrent of visits to the golden arches recently (our basketball team goes there after games) had me ordering a lot of McDoubles and 20-piece McNuggets. I like the chipotle BBQ sauce best. Really nice. Thick. Sweet and smoky. I also tried this the other day: spicy buffalo. I asked for it to put on my hash browns. It was spicy and yet not too overwhelming.
I got this free, without ordering McNuggets. A later visit — they asked me to pay 26¢. Can't blame them. MCD would lose money giving sauce away to non-McNugget eaters.