In reply to Avinash Aujayeb:
Langdale Pikes as mentioned above gives loads of options, with the big routes on Pavey and Gimmer being reachable with other routes on the way. For a big day, starting at White Ghyll, along to Pavey, the summit of Harrison Stickle, then drop down to Gimmer would be excellent.
Rather shorter would be Great Gable with Kern Knotts, Napes and the scramble up to the summit. On a heatwave, you could go round the back for something on Gable Crag too.