(Prices in Australian dollars and based on RRP)
This is a work in progress, if you have suggestions please let me know.

Army selection is very much a personal thing, it's commonly influenced by what stories, movies, books and tales strike your fancy or what you grew up with.

If you want to play WWII Allies and love the movie "Saving private Ryan", then perhaps consider US rangers or GI's, if its "Band of brothers" then US airborne, if its "enemy at the gates" then soviets if it’s "a bridge to far then British airborne", if its "Kokoda" or "The pacific" then Australians (or Japanese to appose them), the list goes on and on.

Obviously on the flip side to the Allies the Germans have some fantastic technology, the fear inspiring tiger I or tiger II 60 plus ton tanks, modern weaponry including very high rate of fire machine guns and inexpensive (and therefore prolific) anti-tank weapons. They come in a number of flavours, early war "Heer", late war grenadiers, specialist units like Fallschirmjäger (parachute troops). There are the minor axis powers as well if you are after something different.

Each of the armies have one or more special rules that reflect their specific strengths typical for their historical performance, for example:

Soviets: Quantity has a quality of its own
Free 12 man squad when building your army list

USA: Move and fire.
No negative modifier for infantry shooting while on the move

German:
Special bonuses around leadership
Extra firepower for machine guns

Buying your army:

Cost wise a box of about 30 plastic guys will set you back up to $65 depending on where you buy them