White or brown or molasses?
Usually brown ..... but have used white with good results. Have even used molasses.
Everybody try it some day ..... make your own special recipe chilli ..... set some aside in a smaller pot and add bits of sugar and test as you go ..... what a difference sugar makes ..... not necessarily makes it sweet .... but completely changes the flavor (very much for the better).
Chilli spices and tomato sauce always have a bit of a bitter or acid edge to them .... the sugar
tames it and adds to the spice and tomato flavor
.... same as kidney beans .... not very tasty by themselves .... great in chili .... and fabulous in chili with a bit of sugar added.
and of course chili is best after simmered for a long time to let the flavors assimilate .... even better reheated next day .... I make a big pot .... portion out the leftovers in bowl size containers and freeze some for another day.
I also only use regular ground beef and do not drain off the fat .... the lean stuff is way too dry for making decent chili.