Nothing tickles us pink more than an outdated championship shirt; our favorite is still when Nike had Final Four shirts for every team other than George Mason, the team whose shirts people would actually want.
Here's a 2007 New York Yankees American League East championship jersey, via the great River Ave. Blues. Yes, we know, it's still possible that the Yankees could come back and win that division, but it's unlikely, and we think a shirt commemorating the first season the Yankees haven't won the AL East since 1997 to be quite the memento. Grab one, before the poor third-world country children grab it.
T-Shirts For Some Third-World Countries [River Avenue Blues]