Mine is usually celery. I need it as a flavoring in sauces (the familiar holy trinity of diced celery, carrot and onion) but rarely use it otherwise except in tuna or chicken salads. Supermarkets usually wrap it up in whole bunches — I end up with limp stalks way before I can use much. Even Trader Joe wraps it up in huge (already trimmed) bags.
But whoa! The other day I saw at Whole Foods small bunches of celery – perfect for any family smaller than twelve or thirteen people. Even at their price-per-pound I saved, and saved from wasting food.
P.S. – I now have another celery use: celery, date, walnut, goat cheese salad. Had it at a restaurant in Hanalei and it was crunchy, rich and nutritious. All at once.