After watching it for several times, I feel that now I will attempt to review this movie.
First I will admit it was a fun kooky crazy type movie in the style of the late 60-early 70s Godzilla films.
Some of the special effects work was pretty good (the X-seijin ship, the GINO, the transformation of Monster X into Keizer Ghidorah).
Some of the monster designs were well done (Gigan's was really nice

, followed by Monster X, and to a lesser extent Godzilla, Angilas, Rodan, and Mothra).
It was nice seeing many of the old gang from the previous Godzilla movies (especially Akira Takarda). Their presence helped make the human scenes a bit more bearable.
Most of the music is alright, a bit ctachy (espcially during the begining battle in the Arctic (it inspired me with an idea for another Godzilla fanfic) and when Godzilla is wiping the floor with his foes).
However there are a lot more bad than good in this movie and the fact that it was styled after the late showa style movies may have also hurt it even more (especially since this was made on the 50th anniversay of the series).
There were some very ugly special effects work (examples include the attack on Paris, the oil refinery where several tanks are destroyed, the minature work especially in the Antarctica scenes, at least two of the battles Godzilla wages with some of the other monsters).
Definitely could have trimmed down the human battles and put more emphasis on the monster battles (first make them longer). Also it would have been better if monsters like Hedorah had been trimmed altogether.
Most of the human cast proved to be unbearable. Although I admit they were funny, most of the time, it was in the ugly fashion (the X-seijin leader and Gordon (especially with the way he speaks his lines) fall into the category especially). Also to have the idea of some humans having mutant powers and all was also a very dumb idea.
That is all I can really say and well if I were to have given this a rating (I would have given this between a two to three stars and that is streching it a lot considing that this movie was supposed to be the 50th annivesary one and with that fact in mine, I would have given this a one star).
To rank the finishes here is how I would have ranked them.
1. Godzilla vs Destroyah.
2. Terror of Mecha-Godzilla.
3. Godzilla: Final Wars.
Best advice: Imagine this more of a madhouse comedy and imagine them as if on set and the monster are bloody drunk and having way too much fun (and for further effect, imagine the monsters chibi sized).

But make sure to never repeat such a stunt like this again for it is antics like this that help perpetuate the stereotypes of the Godzilla movies (it can't be helped but if they had made more serious types of movies, the effects could have been lessened a bit).