I feel that most things we grow, such as beans, tomatoes potatoes, etc. which are staples, for me at least, choosing a 'best' one is very subjective. At home, we all grow in different soils, which has an effect on the crop and we all have personal taste preferences. This is why it's great to swap a sample of something that you either like, or have grown for the first time, with some plot mates. This way you can try before you grow, as the soil is usually pretty much the same across the allotment site, and it saves disappointment if something that someone else thinks is wonderful turns out not to be to your taste.