I'll buy a bunch of raw veggies, chop/peel/whatever them on the weekend, and use them throughout the week, usually in salads. Prep work doesn't happen during the week. I've been known to make "lettuce-free" salads- all of the salad veggies, but no lettuce or greens. What about buying salad greens in smaller quantities from a store salad bar?

I'm a big fan of using frozen veggies whenever possible. Frozen onions in a recipe instead of freshly chopped, sure! Frozen spinach, thawed and drained, instead of fresh in a cooked dish, you bet! Frozen corn/carrots/broccoli as a side dish instead of steaming fresh, certainly! I prepare fresh veggies when I can, but realistically, that doesn't happen very often during the week.

Low-sodium canned tomatoes are a godsend in recipes, and probably the only canned veggies that I buy (other than beans). Most canned stuff is too mushy and salty for my tastes. A quick rinse in the colander and they're good to go!