The last adventure or whatever the diving book is called was fantastic as far as i was concerned! Kick started my enthusiasm after a lay off. Plus i can fit into Pitlamps jacket after 20 year so its a good check on my diet....
Diving wise i find any sump which makes me curious or think 'well i wonder if its worth a look', should come under this heading so the Northern Sump Index should figure! I dont see anyone brave enough to take on the challenge of a revision.. I'm certainly not!
Let's not forget folk the books which most likely started the vast majority of northern cavers starting, the Northern Caves guides. I got NC3 for christmas when i was 12 and it all went wrong from there...