Had to jump on this one. I hate the 'gl' thing myself. Not because I don't wish my opponent well but mostly because I like to sit back in my chair with my feet on my desk and my hand on my mouse. When the dreaded 'gl' shows up, I now feel obligated to take my feet _off_ my desk, sit up and type 'u2'!
Now, my real pet peeve is the 15-20% of my opponents that have calcuated that they have indeed won the match and type 'gg'. Wait a minute! Shouldn't the loser congratulate the winner? Are you congratulating yourself or simply rubbing my face in it? I think I would prefer it if my opponent typed 'I WON I WON!!!'