Axis and Allies - Is there a best country?
Answering the question with AAMC bid statistics

Others have explained why the Axis have a significant disadvantage in the 2nd Edition rules. I'll attempt to provide hard evidence and quantify this advantage. The popular play-by-email (PBEM) site Axis and Allies Members Club (which I have no affiliation with and which I hadn't logged onto in years until I did some research for this post) keeps statistics on the games played by its members.

There's such a strong belief that the game is unbalanced in favor of the allies that the club has introduced a concept known as bidding to even out the game. Before the game starts, each player bids for how many extra IPCs they would need to be given to play the Axis. Then are then allowed to use this money to purchase and place additional units on the board prior to the start of the game. 

Bidding can either be hidden (both bids placed in secret and low bid plays the Axis) or open, where players bid each other down over multiple rounds until someone calls uncle (like the old game show Name that Tune). 

I haven't played in years and looked up my old game logs. I had about a 0.500 win percentage with an average bid of about 12. There is a (fairly vapid) thread on the AAMC message boards asking what bids are running now, the consensus seems to be the low 20s. Lastly, I logged on and checked the game logs for the club's top ranked player. The average bid over his last 20 games was something like 22. The difference in the bids is explained because I always played no first turn Russian attack, which is evidently worth about 10 IPCs to the Axis (because they can save the units in Finland, or at least the fighter). 

So, among the very seasoned 2nd edition players over at AAMC, the consensus is that it's not fair to take the Axis unless the Allies spot them the equivalent of more than 7 infantry on the first turn to be placed anywhere on the game board.

That's a fairly insane unbalance in the game. I believe the only reason it didn't tank the game completely is because although the Allied advantage is large it is also hard to capitalize on if you're inexperienced: the Allies require more finesse to play (flawless execution of strategies like shuck-shuck), often much more than the novice A&amp;A player has.