Listing to a podcast on WWI. It's a really good series BTW and is timely with the 100 year anniversary of the start of the war (
http://www.dancarlin.com//disp.php/hharchive) upon us.
Currently at the point of the Battle of Verdun (1915). Leading up to it Carlin mentions some of the most horrific battles soldiers have experienced. He mentions Stalingrad, Cannae (where Roman soldiers dug holes to bury their heads and suffocate themselves, it was so bad), and Verdun.
Given the conditions, length of time, and objective (Germany was trying to just set up a meat grinder to impose as much casualties on the French and British as possible), I'd have to say being a soldier at Verdun had to be the worst.
Other battles/sieges as candidates for the worst possible experience?
