Let me explain what I think makes a great team name.
1) The name is unique. This means that there aren't other pro sports teams (Cardinals for example), colleges, or high schools with the same name.
2) The name has something to do with the city. Sorry Utah Jazz, but the Jazz is a dumb name for a Salt Lake City team and a perfect example of the opposite of what I am talking about here.
The Mariners, Seahawks, and the Sounders are all unique and describe the Washington coast well. They also have cool logos to go with them which helps.
Is there another city that comes close to Seattle? I can't think of one that across the board is that good.