Hard to choose, a big day multi-piching, winter climbing or on sea cliffs is always an epic experience. My first E tick was my biggest buzz. Freddie's Finale at Wimberry was one of the most satisfying as it took a huge fight with the rock including several falls on the initial fist jamming boulder problem. Razor Crack is possibly my favourite climb.
But really laughing about the day's climbing back at the hut with a beer beats it all.