[LouisWu]

Interesting that some times his face was reptilian, and other times is was very nearly feline.

[Long Cut]

The 1962 version, which was used in "King Kong versus Godzilla", was probably the MOST reptilian he ever looked...no ears and a long, alligator-like muzzle. That suit was called the "Kingoji".

The 1990's suits had a distinct "feline" look which was uncanny onscreen...Godzilla looked more dragon-like in that version.

[Long Cut]

Another thing to remember is that the look of Godzilla tended to reflect the movie he was in...in movies where he was the Bad Guy, he looked more "evil" (see the 1964 version). In those where he was the Good Guy, he looked friendlier. In the 1970's films, where he was "kidie-fied", he looked, well, like a Muppet.

See this article for a detailed look at all the Godzilla suits, and their respective movies.