*Before any starts, lets keep the Armata and its potential out of the discussion*
So I've been having this civil debate with this person over which tank, in general, is superior. I know that there are quite a few tankers and tank enthusiasts here, and to be completely honest, my knowledge of armored warfare probably isn't entirely up to snuff. I'd also encourage the uses of sources, complete sentences, and historical examples and precedents (like the 1st and 2nd Iraq and Chechen wars, testing, etc.) And remember, we all love Russia and America equally, save any jingoism for later...
Some sources so far (I know many of these are probably biased for or against whatever tanks, because of sources of origin, but whatevs):
* http://www.armyrecognition.com/russia_russian_army_tank_heavy_armoured_vehicles_u/t-90_mbt_main_battle_tank_technical_data_sheet_specifications_information_description_pictures.html
* http://www.armyrecognition.com/russia_russian_army_tank_heavy_armoured_vehicles_u/t-90ms_main_battle_tank_data_sheet_specifications_information_specifications_pictures.html
* http://fofanov.armor.kiev.ua/Tanks/ARM/apfsds/ammo.html
* http://dokwar.ru/publ/vooruzhenie/bronetekhnika/sravnenie_tankov_altay_leopard_2a_t_90/13-1-0-45
* http://www.strategicstudiesinstitute.army.mil/pdffiles/PUB1069.pdf
* http://mdb.cast.ru/mdb/3-2002/ac/raowdsmcc/