I kept Savarese for my intern year so I can refresh on stuff for COMLEX 3. Haven't touched it since. I still have Robbins, and Netter, but haven't touched those. I donated the rest to a local library (probably so they can put it on a book sale for $1).
The books I got during residency (Harrison, Nelson, etc) were helpful during residency, not so much after residency. I still have a few specialty specific books (from fellowship) that I keep around, but that's because my NPs/PAs love to go through them every once in a while. I still have my board review prep books (for the specialty boards, not USMLE/COMLEX) ... but they get quickly outdated as well. Nowadays it's all digital so at least they don't take up space ... just $$$
First Aid ... just like the TI-84, it became useless immediately after it has served its purposes. I still have it out of sentimental purposes (reminds me of the time I spent with that book). Looking back, I think I spent more time studying for the board certification exams (I hold multiple certs) than USMLE/COMLEX ... but I think USMLE/COMLEX was higher stakes than the board certificatione xams. The ABMS boards are pass/fail for all purposes (you get a score back, but no one cares what the score is - only if you pass or fail). The results of USMLE/COMLEX determined if I matched and where. Will be interesting to see how pass/fail on USMLE will affect applicants.