I've been looking to upgrade too. I'm on a 3rd gen Core i7. Decided to push it a year though, I'll revisit it mid 2020, mainly because right now the price of video cards vs. performance is just stupid. I added another 16GB of RAM to my current system as a stop-gap, worth it for $65.
If I was buying today though I'd probably go with a Ryzen 2700X. 8 cores, 16 threads, way cheaper than anything Intel has at the same specs.
It really comes down to; do you need faster single-core performance (Intel) or do you run a lot of multi-threaded apps (AMD)?
Intel is definitely still king when it comes to gaming, but it's going to cost you - and it probably won't matter unless you're looking to run at 4K, 60FPS or better.
My old Q6600 has become furniture. It's in a monstrous Lian-Li case that I never figured out what to do with after upgrading to my current system. Now it's become the base for a set of shelves and more or less a permanent fixture.