The problem complicating re-reading "the best" book is how do you know which one is the best? Reading a new one has a non-zero chance of reading a better one. A variation on the secretary problem where interviewing can have a negative cost.
As for a book a day being overkill - you're right, I'm not going to keep this up next year. Normally I read ~80 books but last year I was unemployed for several months and ended up reading >200 even though I was busy looking for work (which involves a lot travel and waiting around which is when I got religious about using my deadtime rather than "killing" time with HN) and I thought fuck it, I'll give it a go at which point I got hired within a month but wanted to see if I can keep going. It's getting really busy with deadlines but I'm confident I can catch up during christmas. For people wondering: yes, I have no family.