Yes I've played Panzer Leader and another one out of the Panzer series. I played Squad Leader a few times in college but it got way to complex for me. My favorites from those days and even now are Empire Builder (Monoploy using railroads instead of real estate), Cosmic Encounters (the BEST card game ever invented), Buck Rogers (board game fashioned after Axis and Allies) and Star Fleet Battles. I'd love to find an online version of any of these. There is one for SFB but it is a pay site and fund are rahter short these days for me. Maybe after my move.
The only other way to play SFB for free is PBEM. I have played SFB by PBEM before with a friend who has time to administer the game. It is a very good game if some one can make a YouPlayIt-like site for it, it better be free...