Hmmmmm, tough calls here but my Top 3 is:
1. Got to go with the Panther. Decent armor and great gun. If used properly it is nearly unbeatable at range.
2. Panzer IV, for a non per tank the gun is good and if used on the flanks of you enemy it can take out any tank in this game.
3. M8, I like it for the speed and the ability to get in quick and disrupt a base defense and it is capable of taking down heavier opponents if you hit them in the side or rear.
My dream vehicle in the game would have to be the SdKfz 234 Puma. It would be nice to have as it has speed and decent firepower above that of the M8 and plus it just looks cool.
BigKev