There's also mrviewer: https://mrviewer.sourceforge.io/
Much better color handling than djv and has some timeline and editing features. Might be overkill if you're just working with animation though
RV seems to be the most used in shops I go to. I tried buying it once but never got a response - wish they just had a store instead of email only. I heard you need to open a support ticket to get a response on anything from Autodesk.
I've also used DJV and MR viewer: https://mrviewer.sourceforge.io/ Both are a step up from VLC and have a lot of the features of RV but they don't perform as well for caching frames. I lean towards MR Viewer usually but it's only available on Windows and Linux.
Also there is BView, https://bufsoftware.com/https://bufsoftware.com/products/bview/. I like this one as well. It's made by Buf and is fairly fast for the job. Available for Mac and Linux.