Right now I have Peas, Radishes, Lettuce, Cress, Arugula, Chard, and Carrots in the ground. The Peas and Radishes just came up and are doing great - based on past experience they should do fine even if we get a couple light snows. I also have a few types of lettuce, spinach and carrots that I planted late last week. There is a very slight chance that a really cold spell could kill them off, but seeds aren't that expensive and I have plenty to spare.
I usually start indoor stuff during the first round of the NCAA Basketball tournament, so I have Tomatoes, Sunflowers, Leeks, Bok Choi, Peppers, Eggplant, Tomatillo, and a bunch of spices doing very well indoors.
I'll start Cucumbers and Squashes in the ground in early May, and will be transplanting the last of my indoor plants outside at the same time.
Here's a partial list of the specific types I'm growing:
Tomatoes: Danko, Glacier, Moskovich, Tiny Tim, Principe Borghese, Lincoln, Oxheart
Lettuce: Rouge D'Hiver, Green Salad, Oak Leaf, Tom Thumb, Little Gem, Quatre Saison
Carrots: Nantes, Chantanay Red Core, Atomic Red, Little Finger, Cosmic Purple
Greens: Arugula, Upland Cress, Swiss Chard
Radishes: French Breakfast, Daikon
I've found that all of these deal pretty well with cold snaps, and I've never lost any of them to spring cold yet.