The church in town is having their semi annual church tag sale, and I am helping the old ladies run it, so that means I will be peppered with such nonsense most of the day. My standard comment to "but you look so good!" is "well, its good to be seen, excuse me, I see someone I have been hunting for, can I catch up with you later?" and then I skip off.
If you cant dazzle them with your brilliance, then baffle them with your BS. HA!