Lots of good points above.
What I would add is that the quality of Soviet units varied widely. Yes, there were desperate counter-attacks of poorly equipped and badly trained recruits, but those were used generally in emergencies as stop-gap measures, e.g. in the early days of Stalingrad. To say that USSR won on such tactics is quite inaccurate. In fact, the chief tools of victory were spearheads of elite troops equipped with the best at Soviet disposal, which increasingly was better in many respects than the equivalent in the other armies. The material advantage shifted decidedly to the Soviets in 1942 and the Axis never regained it. The quality balance is harder to judge, because there are many criteria and the building philosophies were different, but even in that, many would say the Soviets were doing better, chiefly by reliability, practicality, and low cost of the designs. All of that is hardly the peasant wave tactics some have put forth as decisive.
Regarding willingness to sacrifice personnel, I am not convinced that Soviets were that much worse than the Germans. Perhaps so on a company level. Certainly not at the highest levels of authority. The entire idea of 'citadels' that Hitler was so fond of is essentially the same as "not a step back" practiced by Stalin. Just a slightly different way to guarantee massive personnel death for dubious temporary gains. If anything, I'd say the Soviet approach made somewhat more sense in general strategic terms - it was clear time worked for the Soviets, and thus would be a good purchase; it is not at all clear what Hitler's citadels truly bought, as time definitely did not work to the German's advantage.
Regarding the land-lease, it was of critical importance early on while the Soviets were evacuating and restructuring their weapons industry, and later it was of high importance, because it freed up much capacity, which could be directed to tank production. If the Soviets had to produce all those American trucks and jeeps that supported them logistically, they would not have produces the tens of thousands of T34s and self-propelled artillery that actually crushed the Germans.
Regarding Patton's desire to continue fighting, that is just pipe dreams. It was a complete political impossibility for multiple internal and foreign reasons. It was also economically and militarily untenable for reasons others pointed out.
Regarding Napoleon, IMO he defeated himself by attacking in the first place. The terrain, distances, logistics, politics were all against him. He did not have a clear goal or "exit strategy", especially in terms of politics, which incidentally is what destroyed Napolean Europe in the first place. In terms of the military side, Borodino was early on and technically a draw, so it cannot be said that Napoleon was already too weakened to fight effectively.
Russia got a very bad rep due to WW1 and that is why people somehow dismiss its imperial military power. Technically, Russia had a huge and powerful army at the time of Napoleon, benefiting from numerous well-trained patriotic officer corps and loyal and decently equipped professional soldiery. Politically, most soldiers were slaves, being recruited into the army for 30 years without the option to quit. You may think of it as "military serfdom". While horrible by modern cultural standards, it was reasonably effective in providing experienced soldiery in good numbers. Immediately after Napoleon, Russia was the military powerhouse of Europe. It was technological developments that made its military backward again as demonstrated by the Crimean War.
