Shaussies and shorkies. Our female shih Tzus have always had the best personalities and the mixes both had better noses for breathing. The plan was never to breed mixes, the first time we tragically lost our male shih Tzu and the male Yorkie had really robust and temperamentally stable progeny so the puppies were probably the best companions we've ever bred and the second litter from our current shih Tzu was an oops litter even though we separated them, those babies came from my male mini Aussie and have been the most adorable and spunky little babies ever. I've really loved both mixes and would own them simply because I love the shih tzu personality but hate the breathing problems and poor quality of life. Our female is fixed now because one litter was fun but I don't like breeding designer dogs, even though in every case the parents have been pure bred and from really good lines they're still mixes and it bothers me lol.
I'd like to have one or two litters of purebred mini Aussies because my male is an absolute blast to own and I'd love to do dock diving or agility with him and maybe someday his babies.