I really like this example because of its huge scale and variety of objects used, but for mine I'll have to narrow it down a lot more in terms of what I use to make sure my theme stays consistent. There are also 2 cuts I noticed that must have been done because the machine didn't work as correctly as they'd hoped. Animating one instead of building one for real will be much easier for me as all the parameters will be fully under my control, something that I need to mindful of due to time constraints.
Another good example of a Rube Goldberg machine that I found was made for a Honda advertising campaign called The Cog:
I found this video very helpful in developing my idea as it validates my choice to keep the building blocks of the machine part of a consistent theme. The way they only use car parts keeps it very obvious what is being advertised as well making things visually more interesting as components are used for things they aren't normally used for.