Most frozen vegetables are flash frozen shortly after picking, which preserves their taste surprisingly well. So in a way they're actually fresher than the well-traveled greens and beans that you buy from California in the summer.
We keep a couple bags of spinach in the freezer at all times. It's a go-to dish on weeknights. We run it under cold water to defrost, then squeeze out the excess water and sauté with garlic, hot pepper and soy sauce for a dash of greens with our meal.
We also really like this idea from Flickr user pinprick, who bought a big bag of spinach and needed a way to use it up. Her sister gave her this idea:
Steam the spinach and freeze it for later use. awesome! i packed it into an ice-cube tray, then when they were frozen (overnight) i took them out and put them in a bag for later use. i can pull out a cube or two when i want to add them to spaghetti sauce, eggs, or whatever.
How do you use frozen vegetables, and which are your favorites to keep on hand?