Drawings of Dream Crossovers - Transcending Borders

It may not be canon, but a fan can dream! On pixiv, you’ll sometimes see illustrations with the hashtag #夢の共演 (yume no kyoen), which literally means dream crossover. When two or more completely different worlds collide, the results are often surprising, and you might find yourself going, “Wow, why have I never considered that crossover?” on more than one occasion!

Which of these dream teams do you think did it best?