Conti GP5K in 32mm. Wouldn't want to go any narrower.
Have done a ride where was with 3 others, they had 28, 25, & 23mm tyres. The moment we hir anything that wasn't perfect tarmac I just left them behind, hardly slowing at all.
Modern tyres there's little reason for most of us to go super narrow. 32mm or 28mm are a great sweet spot
J