I think no dish showcases good mangoes better then coconut rice. I go slightly nontraditional, and usually opt for non-sticky rice. I then let the coconut milk separate and brown, add a touch of chili, black pepper and enough salt to give it a savory backbone. Cut the mango into smallish cubes and mix into the warm rice. Then add a touch of mint.
The mango fruits look very promising this year, so hopefully, I'll soon have some ripe for picking, and this dish is the first thing to come.
Also, any leftover or over-ripe mango can be frozen and turned into a great yogurt based lassi or coconut milk based smoothie.