While I'm out moving the cows around and working on the farm I'm always on the lookout for wild edibles. Some of my favorites are violas (violets), dandelion, lamb's quarters, wintercress, fungus of all varieties (though I often cook these), bedstraw (thank's jessica for reminding me about this one!), young tender leaves of basswood (tilia), the roots of common grass, wild leeks (ramps) and a host of others. See my post on biophotons for an explanation of why wild edibles are typically superior to cultivated veggies in regards to nutrition and energy (biophotons) composition.
For cultivated species, I like cauliflower, all peppers, radishes, lettuces (especially bibb, yum!), carrots in small quantities, any leafy greens actually, ginger root, chives, tomatoes (maybe a fruit?), okra, and others I'm not remembering right now. But most of those I eat instinctively and for health, I don't get excited about them like I do about meat and fruits (though I only eat fruits in very small quantities). Oh and I will eat sprigs of cilantro and parsley raw, or once in a great while make veggies juices with these as the base. Oh and celery!