Just want to see what everyone favorite colors would be I have seen couple in white and black thought they looked cool. What your choice of color that you think looks best?
Depends on the fish and the rest of the decor. White sand/gravel looks great when there's some rocks and maybe a piece of driftwood but not a lot of plants for a "beach" look. Brown gravel/sand looks great with driftwood and plants for a "forest" look. Black gravel/sand is great to make your fishes' colors pop.
If you do black you are going to need some decent lights (assuming you have a black background). White substrate reflects more light and brightens the tank because of it. Natural is a happy medium and is what I prefer. I have tanks with all three substrate colors/types.