I'd definitely plant something perennial. Clover/alfalfa like you mentioned. If you have alot of weeds, maybe plant some Roundup Ready beans this spring or summer, wait for everything (beans and weeds) to germinate, then spray Roundup to kill everything. You could then broadcast the clover and hopefully it would germinate. By the time the beans are mature, the clover would start taking off. I wouldn't bother with corn.