This way...when the other teams ask, "Who we playing next week?" They will have to answer, "We're playing with ourselves."

Here's some others:
Homerun Brewers
The High Balls
On The Rocks
The Swingers
The Best Damn Team You've Ever Heard Of Or Saw In Your Entire Life, Pallie...THAT'S WHO! (A little long for a T-shirt)
The Bar Flies
Boozer Brigade
We Shoulda Been A Bowling Team
The High Lifes
The Boilermakers
The Bad News Beers

Well...the list can go on for a while.