whats the best thermostat for /6

I was running a 160* last summer but when it started getting cold, and I needed more heat, I went up to a 180* thermostat. Mine runs around 190* on a 45 minute mostly highway commute home in 90*+ heat. Drops down to 180*-185* through shady areas or idling and as high as 195* at 70mph in hot sun. Be sure you're running a good quality coolant in at least a 50/50 mix.