Of all the fruit stands in Kensington Market, Oxford stands out to me as by far the best! (It's no grocery store-style clean fresh bright produce section though...)
I always head to Oxford for my produce needs - the staff are helpful (they will give you boxes if you're about to move!), though not "friendly" per se... but they will answer your questions.
The stand has reasonable prices, and a wide variety of fruit and vegetables. They even have some canned items, and boxes of lettuce (if you're a lettuce snob like me!).
Though there are a few stands in the market that definitely offer cheaper prices, Oxford is the right balance of price, customer service, cleanliness, and selection! You won't find any rotten fruit here!