Not saying what's 'best' but here are some options; I always like Gold, Surf Green, Lake Placid Blue, and Candy Apple red with RW fretboards. Those are my colors for my next builds. It has a maple neck now but the Strat in my avatar had a RW with Olympic White which I liked a lot; a very 'Jeff Beck' vibe. Here are my other Strats with Gold, Natural, and three color sunburst. Two shots of the sunburst with different pickups.
This feels a bit like being asked whether a ham or cheese sandwich is 'better'.
Personally, I've always wanted an Olympic White Strat, but fate has always intervened by putting a really nice Strat in a different colour my way. Generally, I'm not a massive fan of sunburst, but when a see a really classic example of Fender two-tone burst over ash my opinion changes.
I'd probably go for either white, or one of the light blue/greens. Lots of minty goodness there.