What CPU generations does the Dell OptiPlex 5060 SFF support?

The Dell OptiPlex 5060 SFF supports both 8th and 9th Gen Intel Core processors (i3, i5, i7, and Pentium Gold) on LGA 1151, at 35W or 65W TDP. That includes the Core i7-8700 and i7-9700, giving you decent upgrade flexibility within the Coffee Lake era. For a business SFF desktop, two generations of CPU support is respectable range.