I personally like Guadalcanal most among all the Axis & Allies family of games. The only down side for me is that it is a two-player game.
These are the things I like most about the game:
1. The game is balanced. Unlike the rest of the family, it does not pigeon-hole the players into an Axis strategy or an Allies strategy which can be so predictable.
2. The game has a relatively fixed timeline. Rarely will a game go long. You could make the game long, but this would be extremely rare due to the awarding of victory points each round.
3. There is a more realistic application of damage to units. The special dice box is an awesome concept. (There is a better way to apply the randomness of the box by using colored dice, and a printout of the order given in the dice box. This actually improves the roll outcomes to accurate randomness. The box tends to hold the dice from rotating in all directions.)
4. The map allows for land-sea combat. This is very unique to this game.
5. The game is fun, and this is the most important thing to me.