Hmm, let me think
There is some historical stuff in there, so possibly Quicksilver by Neal Stephenson. A historical novel that is fabulously complicated and packed full ideas. I loved it, but I have to warn you that it is one of those books that you have to take time to get into - I nearly gave up but was so pleased I persevered. Neal Stephenson is actually known as a science fiction writer, so that covers the Terry Patchett/ JK Rowling side.
On the historical side, how about Anna Karenina, which is wonderful, Precious Bane by Mary Webb or Someone at a Distance by Dorothy Whipple?
For the romantic, Louisa May Alcott side, I would recommend A Suitable Boy by Vikram Seth.
And then there is the feminist stuff - the Toni Morrison/ Margaret Atwood bits - Telling Liddy by Anne Fine, Helen Dunmore (The Siege or A Spell of Winter), When I lived in Modern Times by Linda Grant or Maggie Gee.
To lose yourself in foreign lands can I add Winters Bone by Daniel Woodrell and Let the Northern Lights Erase Your Name by Vendela Vida. Daniel Woodrell is also a good choice for detective stories.
For the Noel Streatfield/ children's literature side, I would suggest Goodnight Mr Tom by Michelle Magorian, Northern Lights by Philip Pullman (obvious I know), Daddy Long Legs by Jean Webster, and I Capture the Castle by Dodie Smith.
PG Wodehouse is one of a kind I am afraid.
Finally a wild card but a completely extraordinary book that is beautifully written and deals really intelligently with moral contingencies is The Cap or the Price of a Life by Roman Frister.
Hope there is something in there which you have not read yet.