Sprouting Red Lentils Photo from JoePhoto's photostream
Almost any food-type bean or seed can be sprouted to safely eat, but there are a few exceptions. First is to be sure it is not seed that has been coated with a fungicide for planting in the garden.
Sprouts from potatoes, tomatoes, and kidney beans are toxic. Juice of buckwheat greens should not be eaten daily in quantity; it can cause some people to become overly-sensitive to sunlight. It is also recommended not to eat large quantities of legume sprouts on a daily basis.
The most common sprouts eaten in the USA are alfalfa, mung beans (think Chinese food), radish, quinoa, amaranth, broccoli, lentils, and wheat. Others are things like dill, mustard, clover, arugula and in fact most lettuces, but I haven't tried them. I've never done sunflower sprouts either but I understand they are tasty and can be sown in a shallow tray of dirt.
Wheat and barley are often sprouted and grown into a short grass for juicing. I like wheat grass, and it's good for me, but if it has been more than 5-10 minutes since it was juiced, the taste is terrible!
Photo from ★Deb★'s Photostream
Mung bean sprouts have more nutritional value than raw spinach. Try some fresh sprouts in a salad or stir-fry, or alfalfa sprouts in place of lettuce on a sandwich. YUM!