Oh and if anyone cares, my strategy is
40% Paratroopers (Leap Infantry 2 and Light Infantry 2 for weaker nations)
40% Armored Infantry (IFV-1 Crows early on and later on hovercrafts)
10% Engineers and Others. - I am not a huge fan of aircraft or navy as they tend to wreck cities. This just means more for me to repair and less civilians to tax. I am a merciful overlord

The only airforce I use are the Cossack transports that you can buy from Ukraine. They carry a TON of cargo even to rival some sea transports. For the larger nations like Russia and USA, I gathered all the conquered air forces from the other 175+ nations and just threw them en mass to Moscow and DC.
Ground Strategy - 7 Unit stacks per city. This means move a stack of 600 units to an open area. Give them a week or so to spread themselves out until they are all stacked 7 high, then move each stack to a designated city. This works with all but the largest nations and is the most effective way I have found to blitz through a country. The only difficult nations I found were USA (it is so freakin huge) and Russia (they don't surrender until every stupid Siberian town is taken).
Sorry I haven't been to the forums in a long time but I am busy playing!