Kursk and El-Alamein are my picks. These games would use a modfied version of the BOTB rules.
Stalingrad would be a hard one to do since it lasted forever. Rules similar too Gaudacanal would have to be used.
I also really like the Battle of France idea, particularly if it came with new French and German tank molds.
I dont like the mini-front ideas. It would just blowup sections of the current game but not any of the tactical or opertional considerations that a battle/campaign focused game would have.
Also how about a good computer version of A&A with online multiplayer and modding tools.