I think that the title is self-explanatory but I'm thinking about mathematical subjects that have not received a full treatment in book form or if they have, they could benefit from a different approach. (I do hope this is not inappropriate for MO).

Let me start with some books I would like to read (again with self-explanatory titles)

1) The Weil conjectures for dummies

2) 2-categories for the working mathematician

3) Representations of groups: Linear and permutation representations made side by side

4) The Burnside ring

5) A functor of points approach to algebraic geometry

6) Profinite groups: An approach through examples

Any other suggestions ?

reallylike this question... hopefully someone will take a hint and write number (5) and (2) sometime soon! – Dylan Wilson Jan 24 '11 at 10:30Hilbert's Problemsbook (in the Proceedings of Symposia in Pure Math series) from the 1970s. Also, Deligne's articleWeil Iis less technical than you might guess, and there is also the textbook by Freitag and Kiehl. – Emerton Jan 24 '11 at 12:44