In reply to Adrian Berry:
Someone (MattH?) mentioned bagging all the pinnacles in the peak. Think when you tot them up just flicking through On Peak Rock there's more of them than you think, miles more than just Rivelin Needle and Dovedale Church and it even needed somebody to really sit down and work out the logistics for a good weekend, so doing them in a day would probably be quite a challenge.
Other ones I've noticed are (thinking of fun achievments than full on 'in a day' challenges like your examples) - all the Sennen Cracks. Could limit it just to things with Crack in the title (what I had in mind) if you're not up to Super Jam and Samson. Avon Gorge VSs in a day - probably easier than the well known Stanage VSs (TD/ED?) or Stanage HVSs (ED2?) as it's well set up to enchain routes and they're all only half a mile apart (don't people say the walking you have to do in these things is the hardest part - any challenge has got to be easier using accessible crags) 37+ pitches/ 19+ routes if memory serves, would be miles harder to onsight them all in day. Brimham VSs provide a well known good day out. I would've thought there're plenty of good bouldering ones (in addition to the obvious circuits) some Pembroke ones, and maybe even some sport ones. Have the Staffordshire Brown/whillans routes been done in a day? Evil Peak cracks(Right E, Cave, Sentinel, Emerald, Ramshaw etc. etc.)? Peak Bancroft/Allen classics?
Of course If you want you could even climb the country's hardest off widths, take as long as you like!