~~Moved from GR, although it's not exactly a review.~~
This book is AVAILABLE FOR FREE ONLINE! RIGHT HERE!
I think this is technically a textbook, but it's actually a fun read. And the textbook nature means you can dip in and out of chapters.
It is amazingly well-written--it's geared towards a beginner audience, but is so beautifully motivated and illustrated that it's enjoyable for all levels. There are also optional advanced (slightly more mathy) sections scattered throughout.
A really enjoyable and informative read.