My life is slop unlucky. I have missed 14 times with toxic in 19 uses. I want a move that can poison for sure.
Poison Fang: 100 Acc, chance to poison. Cross Poison: 100 Acc, chance to poison. Poison Gas: 85 Acc, poisons. Poison Sting and Poison Jab: 100 Acc, chance to poison. Poison Tail: 100 Acc, chance to poison. Poisonpowder: 75 Acc, chance to poison. Sludge: 100 Acc, chance to poison.
There are more, just look here: http://pokemondb.net/move/all#poison
Besides Toxic Spikes, Toxic is your best bet for poisoning enemies with it's 90 base accuracy.
Al lthe moves that can poison are: Cross Poison Fling (poison barb) Gunk Shot Poison Jab Poison Gas PoisonPowder Poison Sting Poison Tail Secret Power Sludge Bomb Sludge Sludge Wave Smog Toxic Spikes Twinneedle.
The moves with a 100% chance are: Fling PoisonPowder Toxic Spikes
The moves with 100% chance and accuracy are: Toxic Spikes
Source
Baneful bunker Fling G-max Malodor Mortal spin Psycho shift Toxic spikes Toxic thread source Synchronize will also poison an opponent that poisons the Pokemon with synchronize. In gen 6 onward, toxic ignores accuracy checks (ie. can't miss) if used by a poison Pokemon.