Hepatica sp., Liver Leaf, so named because of the shape and spotting on it's leaves. This is often a semi-evergreen with last year's leaves finally rotting away just as it flowers. New leaves will soon emerge.
Bloodroot, Sanguinaria canadensis. A member of the poppy family. They flower before the leaf uncurls, clasping it perhaps to hold it up.
Corydalis sp. flowering unusually early.
Cardamine diphylla, Toothwort.
Jeffersonia diphylla, Twinleaf. Among the hardest wildflowers to witness in bloom. The flowers open and quickly shed their petals 8 hours later.
Trout Lily, Erythronium americanum. These form vast colonies of mostly single leaves in the springtime. It's said that less than 1% of the population will flower on a given year. I'm told growing them on hard stones, so their roots can't grow too deep, is enough to stress them into flowering. Blooming can otherwise take 15+ years to happen! (For those that get tired of waiting, the bulbs are edible.)
Trillium pusillum, Small Trillium... which is actually not the smallest species of Trillium but it is pretty small at around 6 inches.