Round 7 as that's the round I founded my own alliance (FAnG) and got to play with the big boys (Legion Fury, Virus). We allied them and we played an awesome round. It was also the round in which I was the most active and had the most fun in.
Round 10.5 because Angels won that round and we basically made everyone else look rediculous. Eventhough alot used the "but it wasn't a real round" excuse, fact is that it WAS a real round, both on playerbase as on length