i7-6700K... which isn't that old, built it last summer. I had a 8350 before that, which I only recently gave away (still a decent gaming machine with a GTX 970 in it).
About to upgrade the cooling in the 6700K system, see how it fares in benchmarks against my 1700X after I max out the OC for both. Likely the i7 will end up as the dedicated living room gaming, 4K streaming, Vive PC, and the Ryzen build will be my normal browsing, work/productivity, and occassional editing/transcoding (photo, video) machine.