Two G1 buys are pretty standard at this point–2 SB and a sub, or 1 CV and 2 TT. These are both great plays if you want to do dark skies or sea lion.
But I’ve started to do things differently, buying 1 DD, 1 TT, 2 INF and 2 ART (or 3 INF 1 ARMOR/1SUB).
Why?
The DD is a middle ground between having a viable long game fleet and not adding anything on the water so that you can concentrate on ground units. The three ships together can defend themselves pretty well even in SZ 112. The DD is the only way you can destroy the Russian subs–1 of these subs can mess with SZ 125 and stopping this bonus is key. The other (Baltic) sub occasionally hunts the cruiser + transports after the BB is dead, and its a threat you can’t neutralize without a DD, in at least 2 recent games I sub shotted the cruiser, ending the German presence on the water with an otherwise throwaway unit.
On G2, you might as well buy a second destroyer–they often clear the first one and contesting Russian money/SZ 125 is key. If UK or US uses any subs to hunt your money, having these 2 DD early is useful. After G4-G5, no German navy is going to be able to step with the UK/USA combined fleet if it comes, so this buy is a middle ground between spending the money on moscow bound troops vs wasting too much money on subs/carriers etc.
I buy the TT because it may appear to be sea-lion like to some players, and some threat is built there (hopefully so they don’t buy 3 UK SA armor, if they do, Allied control of Africa is pretty much going to happen by UK 4-5). I don’t really do sea lion (ever), so the actual underlying idea is to 1) stick troops into Norway while you can because that is the big late-game vulnerability to KGF 2) use the transports to stick more slow movers into Leningrad so the defense of Leningrad and eventually Moscow are hopeless.
I buy all the troops because, after turn 1, Germany doesn’t have any infantry to grab. Troops on France are not available G2, and all the infantry is dead. The 2 guys on Denmark got shuttled to norway on G1. You do of course have abundant infantry in Poland/Germany but they are already marching that way, so grabbing them with transports only saves 1 step, whereas, you can move them all the way to an unscreened Leningrad with your 2 transports.
There are plenty of times that Russia omits to move the Cruiser into screening position on R1, this move is the only way that Leningrad could live that extra few turns.
Other buys, such as 1 ARMOR 6 MECH or 2 SB are probably better in general because they’re part of a strategy of forcing a quick, decisive ending by destroying Russia. However, in bid games and against better players, a more conservative approach is called for, which involves denying Russia 1) the 125 bonus from war start 2) convoying your Norway $3 away 3) getting Leningrad on the earliest turn possible to deny them that money and capture it for yourself.
Unfortunately, the only job the infantry have is to hide on Norway or Finland pretty much the whole game to dissuade or contest a Norway landing, but this is a viable use of your guys and time because the only really successful KGF strategy I’ve fought against places US factories on both Norway and Finland.