Bump! I just watched this last night (Sony DVD) 'cause I had a nagging desire to see it again.
Probably one of the most entertaining Godzilla movies, I think, and it's hard to see why it's considered the worst (I realize people didn't like it because it was so much unlike the prior, more epic and urban Godzilla films). This was one of my favs as a kid too. It's just a great, fun, high-seas adventure! Too bad they didn't throw in some pirates...
Since I watched the international version, there are some differences from my childhood memory version that make it even better. Some people may not like the surf rock music that plays when the jets attack Godzilla, but I think it's perfect. I love that part.

The same kind of music was thrown in during part of the second Godzilla vs. Ebirah fight, and it worked so well! I really like the Infant Island dance numbers, too. Otherwise, I agree with all the above sentiments, especially on the characters, who are memorable and endearing.
Reflecting my current infatuation with the movie is my new desktop wallpaper:
(Godzilla contemplates my Winamp playlist...)