The most potent strain I've had is 'Malawi Cob'. It comes from Zambia, Africa and the put the hash in a bamboo shoot, and wrap the whole thing up in the leaves. Sometimes it comes so well packaged that you smoke it straight out of the bamboo shoot.

They make it by taking the weed there and smashing it up against the wall until it becomes a pulp. Then they boil the pulp in water and let it dry out in the sun. The shit is SO potent that a little fingernail full is enough for one hard trip, and it usually comes in 1-foot pieces. Intense high, unfortunately an indica strain so if you smoke too much you pass out quickly.

I love Zambia!