beans and peas are good but chickpeas are better. sunflower and
lemon/orange/grapefruit are possibilities also, though it is wise to
scratch the hard coat beforehand (with sandpaper). Any seed large but
not so large that it will take a long time to sprout. If you can start
the seed ahead of time, mango will provide a show once it gets out of
the shell. In the summer, watermelon and melon seeds sprout by the
thousands in my compost pile, and they go fast. One could also buy
wheat at the health food store. That, too, goes fast.