Well if you have ample pots and compost you could have a go at the lot.
If you have to prioritize, I'd put tomatoes ahead of beans and sweetcorn last. You are only likely to get one or two cobs per plant at best and unlike an allotment bed of sweetcorn pollination may be tricky. My allotment sweetcorn always seem to develop huge roots. I'd guess they might struggle in a pot.
Four good tomato plants could easily yield 40lbs of fruit. I'd take that ahead of six sweetcorn cobs. Just my opinion of course.