How about a non-British suggestion: Hans Fallada, _Little Man, What Now?_
(1933). It was in a paperback ($14.95) a couple of years ago.
Instead of _All Quiet..._, I use Wilfred Owen's war poems in Western Civ,
and they have been very successful with the students both in terms of
content and in helping them learn that poetry can be really powerful and
accessible.
Definitely use something by Orwell. I've used _Road to Wigan Pier_ and
_Down and Out..._, and the latter was the more successful. I'd like to try
_Keep the Aspidistra Flying_ myself. Also definitely use Waugh.
Finally, how about Virginia Woolf!?!?! I know you asked for novels, but
_Three Guineas_ (1938) has worked well with my advanced undergraduate
courses. _To the Lighthouse_ (1927) would be the most accessible novel.
There is also a very good video version of _A Room of One's Own_ (from BBC;
aired on Masterpiece Theater a few years ago). It sacrifices some of the
richness of the book, but makes it a lot more approachable for students.
I'm enjoying other people's suggestions and will use some myself!