What a fun topic! This is of course making us all the same age despite what age the characters are in their books. I'm thinking 16-17 because we would be able to drive to hang outs and all the crazy things our group would be up to after school.
Gen and Irene for the Queen's Thief Series by Megan Whalen Turner
Lord Peter and Harriet from Strong Poison, To Have his Carcase, Gaudy Night, and Busman's Honeymoon by Dorothy Sayers
Howl and Sophie from Howl's Moving Castle by Diana Wynne Jones
Ron and Hermione from Harry Potter Series by J.K. Rowling
Kate and Christopher from The Perilous Gard
In addition to these fine people and myself we will add my husband. And with that this would be the table with the smartest yet laziest students (the boys), contrasted with the smartest and everyone knows it students (the girls). There would be a whole lot of eye rolling, flirting disguised as snarky flippant conversation, and quite a few political debates. There would also be a whole lot of trouble.
Who would you have at your lunch table.