In reply to MischaHY:
In a heatwave, go to Scafell and do the classics:
Central Buttress: it may only have 1 5b pitch, but it's quite a mission. Brilliant route.
Saxon: The main pitch is a killer. Lovely bold climbing on little holds followed by a rock'ard crack (well it is when it's still a bit damp).
Ichabod: A big pitch with a testing traverse and then a whole lot more steep crack and groove climbing.
Roaring Silence: Liked the bold traverse on Ichabod? More of that, interrupted only by technical cracks with hard-won gear. And a scary roof pitch above. Beautiful.
Pavey is great too. Astra is a brilliant E2, combinations of Arcturus + Aardvark would be a good combo. Cruel Sister at E3.
Gimmer is kind of multi/single pitch hybrid. Excellent routes - Whit's End Direct is one of the best E1s ever, Equus is one of best E2s ever. Eastern Hammer (E3) is reputedly nails. They are single pitches, but they're 40m long and complex, starting on a ledge which could be accessed by the unsettling pushy-offy ramps of Intern or the slightly less good Crystal.
For a bit of convenience, but still multi-pitch, Castle Rock is excellent. Rigor Mortis is really quite hard at E2, the E1s are great.
And Dow - great crag. Samba Pa Ti (E2, access by Isengard HVS) is absolutely fantastic (and a rare steep, super-juggy, exposed soft-touch), Pink Panther is hard and bold (a single pitch but could be linked into something like Catacomb perhaps?). Sidewalk (E2) is classic but tails off into choss higher up.
There's a start anyway. My next destination is Black Crag (Borrowdale) for this sort of thing. Looks great.
The climbing in the Lakes is fantastic.