Yesterday, I saw Betty Boop and the Little King. It was made in black and white in 1939, and I mention it because there’s a rather impressive 3D effect at around 1:50 (then again later).
Here’s a link from Archive.org if you prefer, but I had less luck with their embedder.
What I like about it is how it was achieved. It was done the same way all visual effects in the 30s were done: they built the thing and pointed a camera at it. That approach wouldn’t even occur to us now.
They had an entire rotating set built to create 30 seconds or so of footage.
I really like a lot of the CGI stuff we have now, and when it’s used well it’s just flawless, but it’s almost impossible to feel a sense of wonder at a visual effect in a modern film because it’s sort of clear how all of them were done. And there’s an elegance to the 1930s solution that the modern one lacks.

If you want to make yourself feel better, I recommend watching the special features on some Aardman DVDs.
I must add a like button to this comment thing and then like your comment.