The coolest rides we've had was on our Martin 242, racing in Howe Sound with 20+ knots and flat water, planing into the double digits with the kite up. On a par with that was surfing down the rollers off St Vincent on a Bene 36.7, rushing into the teens there too.
But I'd have to say the sweetest boat I've been on would be our recent week on a friends' Passport 40 in Mexico. Solid, steady, extremely well mannered, dry and comfortable... verging on luxurious.
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)