Hmmm - interesting thread.
Having taken up a lot more time reading in recent months, I revisited some of the classics, amongst the non-fiction categories I found "The Ragged Trousered Philanthropist", "Animal Farm" and "1984" a great read - but scarily real today.
On a similar tack, contemporary books such as "Bad Science" and "Bad Pharma" from Ben Goldacre, and "The Spirit Level" would be a good selection. Equally interesting and scary, and annoying, and sad, and make you angry too.
Sounds odd I know, but I found the "Wallander" series from Henning Mankel a great relaxing read, along with Stieg Larsson's work.
Worst books - for me - I've tackled this year were "The Grapes of Wrath", and a Jo Nesbo novel - both struggled to get going, but the Steinbeck book just seemed to be overly descriptive and a bit long winded.