In reply to joe.91:
From this year/last year the following spring to mind
Surprisingly clean:
Thirlmere Eliminate, Castle Rock
Totalitarian
Main Slab Route to the Perch, Gill Crag
Somewhere in between clean and dirty:
Bleak Howe Buttress
Nexus, Eagle Crag Grisedale
Gethsemene, High Crag
Glorfindel, Neckband
Burger, Upper Swirl
Unsurprisingly dirty:
Myth of Fingerprints, Fat Charlie's Buttress
Artefact, High Crag
Banzai Pipeline
Filthy:
Bloodaxe, Carrock Fell
Far from the Madding Crowd, Thrang Crag
Too Baldly Go, Harrop Tarn
The list goes on...