Best supplements!
The best three Supplements AP has made and are in stock are: Marianas 1944, Spearhead Division & Armata Romana. The main reason besides the subjects, is that they only require ownership of one game. Also, they come with counters and maps for Marianas.
Since I have nearly all the 3rd Edition boxed games, ownership requirements were not much of an issue for me. Airborne Remastered is my first choice. Good scenario mix, most kinks worked out, not much weirdness. Close follow ons would be Fronte Russo, White Eagles, Arctic Front (not Deluxe), Workers & Peasants, and Invasion of Germany (book or components).
I pretty much got rid of all my older PG games and supplements related to those.
I would go for Mariannas. Two new maps and a small set of new counters, additional interesting scenarios. This is really enhanncing a boxed game.
War on the Equator and Fronte Russo for me.
Playing the Ecuadorians is a unique experience due to their very low morale. It's also the first supplement I played through so War on the Equator holds a special place for me.
Fronte Russo is the supplement that gives me the best feel of the hopelessness of the East Front. I will finish it someday.
The ones that I played and really enjoyed -
1. War on the Equator
2. Blue Division
3. White Eagles
4. Arctic Front
Ones that I haven’t played but really want to, jast based on reading the scenarios in the books:
1. Hopeless but Not Serious
2. Edelweiss
3. Fronts Russo
4. Marianas
This is only based on historical WWII - this doesn’t include Cold War, Long War, Second Great War, PG Modern, or Infantry Attacks offerings.
Winter Soldiers
Romanian/Gross Deutschland => Broken Axis
North of Elsenborn etc. => Invasion of Germany
Black SS