In a rut. Give me your books that span generations

I'm in a bit of rut. I'm rereading everything I have right now because I can't focus on the process of picking something out. Typically when this happens I go back and read Beach Music because I simply love it and the multiple timelines entice me into different genres. The issue is I just reread it and this time it didn't work as it usually does. So based on that info, any ideas? I'm down for a challenging read and will pick up anything other than the scariest horror or the raunchiest romance. I'd prefer a stand alone as opposed to a series but am open to a trilogy if you really think it will grab me. Thanks in advance from an avid read who is stuck.

Edited because I didn't proofread