From what I've heard around HookahPro, Tangiers and Nakhla give the best buzz.
Things that can help for a better buzz:
- Like Malfean said, empty stomach
- Smoke much in a row. You will get a higher buzz if you keep pulling. If you get 20 pulls in a row, you probably will get a better/higher buzz than when you get one pull, stop for a min and take another pull.