Strictly speaking of TV/Film, in Batman '66 Gotham was just a relatively normal looking city of the time. It wasn't until Batman '89 that we got the dark, brooding Gotham that we are so familiar with on film.
Question for those who are familiar with the comics: Was Gotham always the dark brooding place of later films in the comics, or did it go through a similar transformation over the years?
In the early Batman comics the city was often shown at night, giving it a dark atmosphere, and a surprising number of stories took place in Gothic mansions and cathedrals, however, there wasn't really any effort to make it stand out by itself - unless they were related to that issue's story, you wouldn't see those castles or mansions right in the middle of Gotham's skyline.
Then comes the late 40s and 50s where the focus changes to sci-fi and by then Gotham is just a generic city. In the 70s (and for a bit in the 60s, but this was interrupted due to the tv show blowing up) there was an effort to make Gotham darker again - both often showing it at night and even during day you could see stuff like red or yellow skies to give it a weird atmosphere. This also came alongside more stories using castles or dungeons as set pieces. However, yet again, Gotham itself was mostly shown as a standard, but dark, city when you saw its skyline for example (often with a giant moon in the background).
Gothic imagery in the architecture itself noticeable even in random shots of its skyline really became consistent only after the Burton movies.
