Asking "preferred strategy" questions opens the door to individual opinion. I will try to avoid this by employing simple mathematics.
"Germany First" is the most logical path to choose, but not by ignoring the Pacific theatre.
The U.S. can typically build with impunity during the entire game, outside of the reach of German or Japanese strength. Once a large enough force is gathered on the eastern coast, (turn 3), they can head on over to Africa, and from there they can threaten either southern or western Europe. Meanwhile, each turn the U.S. can build a couple of transports and units to load, thereby forming a continuous loop of troops to Europe. And, in a short time, the U.S. can stop building transports and focus on the ground forces (and some air), thereby making the situation even more acute for Germany. Add to this the U.K. building its own fleet up, and Germany is soon a non-participant in the Atlantic. If Germany tries to keep pace with the U.K. and U.S. in the Atlantic, Russia will never be threatened. Germany simply doesn't have the economy to seriously engage all three allies at once.
The German player cannot ignore this viable threat, and must draw land forces from his eastern attack on Russia to protect his flanks. This, in turn, will allow Russia a measure of calm before the scrap at the gates of Moscow.
If the U.S. forsakes the Atlantic, the U.K. doesn't have the forces to threaten Germany with any great strength, and Germany can pour its malice directly upon the Soviet Union. And, although the U.S. has a strong economy, it cannot bring many ground troops to bear against Japanese holdings for a few turns, and when it does, the Japanese are in a far better position to fight back.
Mathematically, about three turns in, the Germans will have a revenue that is close to the combined Soviet Union/U.K. income. The problem for the Germans is that they only get one turn out of five to employ this apparent bonus. The Allies can bring three turns out of five against Germany. The Soviets and British have similar advantages of being able to trade space for time, although the push on Moscow is a real and imminent threat.
One 'loop-hole', if you will, in the original A&A is that Japan is out of position for most of the war. Unless the U.S. forsakes the Pacific entirely, and Britain doesn't fight for India, Japan will poke around Asia for a while, and maybe take some islands here and there, but for the most part, there are no large gains to be made as the Japanese. True, they have an impressive naval and air presence, but there are simply no big ticket targets for them. So, they build and build and build, and slowly spread around their area of the board, but unless the S.U. player is completely careless, Japan can never truly threaten Moscow, and, by the time they do get tanks to Moscow, Berlin is either a smoking ruin, or the Allies were inept and Germany and Japan are putting the pincer movement on Moscow. And the idea of Western U.S. falling is ludicrous, unless, of course, the U.S. player unaware of the impending doom of 10 Japanese transports slowly making their way across the Pacific Ocean.
So, to answer the question in one sentence: send as many troops as possible eastward and keep constant pressure on Germany. If the Axis player still wants to play after Berlin falls, well, enjoy nuking Tokyo.