Hat. Wish there were some nicer full coverage hats instead of all the baseball style hats, but I don't see many that keep the sun off you and don't look stupid.
Use to be nothing on cloudy days but visor on sunny ones but past couple years been hats on sunny ones and I still like nothing when cloudy. And to be honest, when we had a similar thread last year many mentioned the bad about too much sun and the serious problems it can cause for those who golf a lot. Since then I always wear hat in the sun and also always pop up my umbrella on my push cart to walk under all the time. And take my hat off while under it to help release some head heat too.