Yes, they're all fine. 'Favourite' can be used as an adjective (my favourite book, my favourite books, my favourite one, my favourite ones), or used as a kind of noun (by adding an 's' - these are my 'favourites') By the way, either spelling is fine : favorite (Am Eng) or favourite (GB Eng) , but it looks a bit strange if you mix the two!

I think they are all ok. "favourites" is used as a pronoun, not an adjective. You can say "one of my favourites" (pronoun) or "one of my favourite books" (adj) or "My favourite ones" (ones -->books)

Your three examples are all correct. Note that in example 1, it would also be possible to use the singular "Apples and bananas is my favorite." This would imply a dish consisting of apples and bananas together. I've actually never heard of such a dish, but the phrase "Spaghetti and meatballs is my favorite" is quite common in the U.S. Note that in this usage, "spaghetti 'n' meatballs is pronounced almost as a single compound word.

All three are correct. Note: "favorite", contrary to the imagination of some of the friends writing here, is never a "pronoun". This is 胡说八道！ You will have seen on your computer toolbar "favorites" that store the addresses of your favorite web pages. During this time of the World Cup, perhaps you should also learn an additional definition of "favorite" (USA) or "favourite" (British): "The competitor thought most likely to win a game or contest, especially by people betting on the outcome". Example: the German team is a strong favourite. Learning is also fun. If you have children, watch the following song with them: "My Favourite Things" by Julie Andrews from the Oscar-winning film, "The Sound of Music". The movie in fact appeals to all ages. It is about love, the joy of life, the importance of humanity and the necessity to be strong in the face of dictatorial regimes (in the case of the movie, the Nazis).

1. Apples and bananas are my favorite. (no 's') 2. These two books are my favorite ones. (ok, but you can leave out 'ones' also) 3. These two books are the best ones I've ever read. (ok, but you can leave out 'ones' also)