The problem of course with selecting MVP's is the criteria you use because the official guidelines mean different things to different people.
My choice in the AL would probably be among the following five:
ARod, Soriano, Tejada, Giambi and Ordonez.
I think if you go by pure numbers I would pick ARod followed by Ordonez. Soriano's numbers are great but in this group he falls short in RBI's and walks (OBP). The 40/40 feat is irrelevant because not only has it been done before (and ARod didn't win MVP when he did it) and 30/30 (even high 30/30) has become more commonplace than it has been.
Problem with ARod and Ordonez of course is that they play on losing teams. And if the answer is who is the most valuable to their team does it really matter about these two because they weren't good enough to make their team win. Obviously a lot of that has to do with supporting cast which Soriano, Giambi and Tejada have more than these two guys. Take ARod and Ordonez away and you still have a losing team. If it was MVP to any one team I would go with Ordonez.
I think for a player on a losing team to win it their numbers have to be so dominant over any player on a winner as to make the issue moot.
Among Soriano, Giambi and Tejada I would choose Tejada. All three have had great consistent years and are surrounded by other great talent. However, Tejada has less offensive talent around him than S and G. Adding in the fact that Tejada plays SS and has become a leader of the team that lost Giambi and has been clutch when most needed sways my vote to him.
NL should be among Bonds, Kent, Guerrero and Pujols. Guerrero is a statistical monster and certainly has been instrumental in Montreal finishing (probably) second to the Braves and over .500 when no one thought they would. He also has less talent around him then the other three. But his team didn't win and his stats don't overwhelm the competition.
Pujols has great stats, his team will win the division and the talent surrounding him doesn't compare to Bonds/Kent especially consdering they are on the same team. (Note - Pujols will likely have more RBI's after his first two seasons then any player in BB history not named Joe D).
Between Bonds and Kent I think the nod goes to Bonds who will lead the majors in batting and set records for most walks in a season and hightest OBP. His K/BB ratio is fucking obscene as is his HR/K ratio. Only 43 K's to date. No one wants to pitch to him and when they do he produces. Add in the fact that he will slug .800 and his total of hits and walks will total 350 times on base and no one else is even in the same zip code.
The vote is Bonds, Pujols, Kent and Guerrero.