I am addicted to Haste pots.
Shabadu - WWS and look for "Haste" under the Buffs section. But as Praetorian said, I am often forced to save my pot timer for a health or mana or protection potion. I'd use them more frequently but making sure I stay alive is worth more DPS than 15 seconds of haste. Using them with drums and bloodlust up can lead to sub 1.0 attack speeds, which is pretty absurd, especially if I time it to come up with my other trinkets and Shamanistic Rage.