2600K-2700K-2500K-3770K-3570K
If you pretty much built a computer with one of the said CPUs in 2010 to 2012. You were pretty much set for the next 8 years. IPC gains were extremely significant over pre SB architectures.
Before that, maybe I could recommend Q6600 from 2007. If you got that in 2007, you were good for a long while.
I dont know much about AMDs history to be honest.