I usually do the stew/gravy type cans for Kongs, it seems to "pour" into the Kong better. I usually use Earthborn, Fromm, or Lotus, occasionally some Wellness or Halo.
I do a lot of freeze-dried Stella & Chewy's, Primal, or DNA in Kongs too - I stuff it in dry, and then run water through it for 10 seconds so it freezes harder.