There's an MMM blog post, and threads on this I think.
If you can, buy manual not auto - just simpler, cheaper, and generally more fuel efficient.
Pontiac Vibe/Toyota Matrix
Honda Civic but avoid the early 8th gen I think, due to head cracking issues... so either 7th gen (we have a 2004, manual, it's fine), or 2010+
Toyota Tercel or Echo if you want smaller
Hatchback is more functional than sedan/saloon.
If you're doing lots of city driving, a Prius may be worth it (probably not vs a Civic, assuming 2004...); long distances, get a TDI (or, again, just go with the Civic).
Yeah... Corolla or Civic from 2004, manual transmission, can't really go wrong.
*Edit* - I should say I don't actually *like* our Civic, but it's a great vehicle for my wife who drives quite a lot. I have a Crown Vic. Just.. because.