I recommend the Thermal Grizzly Kryonaut, works well for me.

Don't overthink it too much. Most name-brand thermal pastes will work fine. I'm using the Noctua NT-H2 on my 13900K and temperatures are good. Just make sure you apply it correctly (pea-sized dot in the center) and pair it with a beefy cooler. The 13900K runs hot, so your choice of cooler is more important than minor differences between thermal pastes.

Kingpin Cooling KPx is thinner than Kryonaut Extreme, so easier to spread.

I've had great results using Noctua NT-H1 thermal paste on my 13900K. It's easy to apply, has low viscosity, and provides excellent thermal performance. Plus, Noctua is a trusted brand in the PC cooling space. Just be sure to clean off any old thermal paste from your CPU and cooler before applying a fresh layer.

Noctua NT-H2 is also OK.