I have one 256GB SSD with my OS and stuff on it, and two 2TB HDDs. They all have around 10% space free. What size drive should I get as my backup? Also, any specific recommendations that would be good for me? Preferably external.
How much of that space can't be recreated in a different method (re-download, re-rip, etc)? How much is very dynamic data that should be backed up in more than one copy? Those are the kind of questions YOU need to answer to help size your backup capacity.