Which Exeggutor moveset is best against water type

Confusion + Stab against water DPS= 17.50
BS +Stab +SE DPS = 15.3

Confusion is still on top.

Bullet Seed / Solr Beam Exeggutor is the best grass attacker available right now. To anyone who disagrees, feel free to check its stats. Some might argue Vine Whip / Solar Beam Venusaur is better because of its fast moves but then again... Exeggutor's stats makes him the clear winner. Now to answer your question... Confusion's DPS coupled with Eggys stats would outrace all its current movesets if we're talking about damage but Bullet Seed's STAB and energy gain would edge out when dealing with water types. Powerful STAB to charge your stellar charge move is a clear winner.

I just ran a couple of quick Pokebattler simulations, which show that BS/SoB is several seconds faster than C/SoB in defeating a WG/AT Vaporeon.