Seattle.
It's where my best player had his best years so it holds a special place in my heart. While I've been with just about every team in one way or another (some version of every team except QUE) I always deem Seattle to be the team I enjoyed the atmosphere of the most. Plus, if I recall, Seattle is the only team I've one 2 cups with (Beketov and Young)
With that said, Helsinki and Cologne are both tied for a close second place.