So CN did a crossover between Uncle Grandpa and Steven Universe. I remember Nickleodeon did a Jimmy and Neutron and Fairly Odd Parents crossover, and Disney did like four with Lilo and stitch. What do you think of Networks creating crossovers between their shows? What actually possible crossover would you like to see with current airing cartoons?

Gravity Falls and Star Vs.?
Adventure Time and Steven Universe?
Or all crossovers are shit?