I use the TUSA Platina from ST.
Tusa Platina Hyperdry Snorkel, Snorkels, Tusa, Tusa Platina Hyperdry Snorkel
It is very low profile and
DRY. I got a black/red one - just a little red on the mouthpiece valve. When I spit it out of my mouth it is out of the way. I use it most of the time for freediving and SCUBA.
When I am in rough seas or racing I tend to use an Aqua Lung Impulse 3 non-flex. It has a large bore for unrestricted breathing and a slightly longer tube for white caps. The flex tends to oscillate when moving through the water fast or when surfacing.