Here is what I found:

Two little Golden Chard plants that decided to come back up. I wasn't planning to plant chard this year because we just didn't use that much of
it last summer, but these two plants should give me just enough.A whole bunch of little dill plants had sprung up from the seeds dropped by last year's plants. I was planning to plant some anyway, so I dug and moved the seedlings into a semi-neat row.
Last year's parsley has come back (well, it is supposed to, being a biennial, but I guess I never expected it actually would come back) and has already grown big and bushy.
The biggest surprises, though, were these:

twin green onions that sprouted from seeds I planted last spring, and a carrot that I apparently missed pulling in the fall and which had sprouted a nice new top!
Inspired by my garden surprises, I decided to use them in my fried rice for dinner. The green onions were great, but (surprise!) the carrot was really terrible. Apparently, overwintering your carrots and using them in the spring is a bad idea.
Of course there are always some bad surprises in the garden, like when you realize the red, ripe strawberry you saw yesterday was eaten by a chipmunk, or when the late blight kills all of your tomato plants before you harvest a single one. Most of the surprises are good, though, like finding that first sugar snap pea, the very first produce from your garden (and of course this is best if you are by yourself and don't have to share the first one with anybody else- it is your garden after all); or finding a hilariously large cucumber that your husband totally didn't see when he was tending the garden while you were away; or seeing that perfect row of seedlings pop up one day, when they weren't there the day before.
Soon there will be summer surprises in the kitchen as well, like those pea greens I wrote about last summer. I'll try to post recipes as they spring up!