There were always two or three "Ooooooh Mother!" bits for me - top and bottom of Barregarro, buttock-clenching to take honestly flat out even on a tiddler (best handling bike for me here strangely was the proddy 250 Kwacker!), and first time through St Ninian's crossroads at the top of Bray on a flying lap on my TD3. All through practice I was doing a single lap on this, a lap on that, so speed after the start/finish straight was nothing like I was suddenly faced with first time I went straight through!
Best fun ever was through Kirkmichael - especially if first one through on dawn practice. The noise, the sensation of speed, the thought of all those good folk being shaken out of bed by an unsilenced twin 2-stroke at 100mph plus past the 30 limit signs......
The smell of wild garlic at Bishopscourt, keeping a careful lookout for the tree with the big white 'K' painted on in Quarry Bends, the waterpipe running down the wall on the left as a peeling-off point for Union Mills. There are just too many.