If you wanted to get into a debate about it, green small dot would win hands down. Green stands out against red the best (the color of your enemy) and small dot allows greater accuracy due to less space being covered.
Personally, I like small crosshairs with bloom off better than dot tho. Color depends on the hero (Helps me keep heros straight so I don't try to deflect with reaper in the heat of the moment

). I like crosshairs over dot 'cause it's a little easier to see if you're moving your mouse a lot (constantly flipping 180ยบ's with Genji, for example) and the + style helps me judge my flicks more accurately.
This post was edited by Dragonkilla8 on Sep 8 2016 11:51am