How do you find Duriel again?

Solution 1:

If you created the game and still remember the symbol, it shouldn't have changed. Otherwise, the symbols on in the Summoner's chamber in the Arcane Sanctuary show the false tombs. The one symbol that doesn't appear there is the true tomb.

The 3 prime evils (also NM Andariel and Pindleskin) are better choices for boss farming as they drop better loot.

Solution 2:

I checked a couple threads, and it looks like you need to revisit the summoner in order to locate the correct tomb. However, it would also seem that Duriel runs are not that popular since the other act bosses have better loops drops, and are easier to kill.

Solution 3:

Also, If you find a glittering chest, then you know that you are in the wrong tomb and can start your search in the next one. Only the wrong tombs have the glittering chest. Maybe that helps to speed things up a bit.

Solution 4:

Unless you're dead-set on exploring all seven tombs, here's one method I use:

I start from the rightmost tomb, head left until I find the correct tomb, and then go in, ignoring any other tombs.

Then the leftmost tomb on the map will always be the correct tomb, because tombs further left won't show up on the map.