My main row is:
Super Pershing (E): 6475/751, M3 Satan (E): 4690/525, T-62: 6536/612, Panzerwerfer: 2830/99, Jagdpanther: 3135/565.
That wipes out most things that I run across, with backup from my other units dropped in as necessary.
I do have an Object 279 (E) at 10153/341, but I haven't found a great use for her yet... sometimes her invulnerability barrier comes in very handy but sometimes she just flops over dead and at a 6 gear cost that's really rough.
Mediums just seem to be the best all-around unit, give them decent support from TD or Artillery and they can clean up. The main goal is to kill the enemy tanks before they can build up a deathball of their own (so your tanks take less damage) and heavies just don't seem to do enough damage to accomplish that for me.