As mentioned ARMA II and PR mod for BF2 has some decent tank combat. WWII Online is an MMO set in WWII which meant to have good tank combat but there's a monthly sub to pay and all that so not really a viable option. I'm probably wrong since I'm not expert but I believe the most upto date simulator which is counted as one of the best is Steel Beasts Pro PE, however, that will set you back $125.
Forgot to mention Steel Fury: Kharkov 1942