Excuse me there. The problem is that Axis haven´t got the best units in almost any category any longer.
"Best" describes the biggest utility and effect for cost.
Best Infantry: Imo it´s dual Bren Tommies
Best MG: Maxim
Best Mortar: US mortar
Best light vehicle: T-70 or Stuart
Best Medium Tank: Cromwell
Best lategame tank: Comet
Best AT vehicle: Firefly
Best heavy artillery: Calliope or land matress
The only aspects I see an advantage in are AT guns (Pak 40) and Super heavy vehicles such as the KT (which are however easily hard countered).
Germans are in fact not competitive this patch.
This is all a matter of opinion. Infantry is a wash, since they all have their ideal ranges and uses, but Tommies are solid at range (like Obers), while Rifles with BARs and Penals are great assault infantry late game.
MG: MG42. Hands down.
Mortar: USF M1
Light Vehicle: Depends on role. Stuart is a good all-rounder but Luchs and Puma excel in their roles. T-70 is a wipe machine.
Medium Tank: I'm partial to the P4. Crom is fine against infantry but less effective against armor.
Lategame Tank: Comet.
AT Vehicle: JP4.
AT Gun: Pak. No contest.
Rocket Arty: Walking Stuka.
Germans are plenty competitive... although every time I play OKW i wish they had the MG42 instead of the garbage MG34.