I'm a big fan of the android tts. A bit robotic, with quite a few prosodic errors (which is simple to get used to), but so convenient. No need to hunt for audiobooks - actually in most languages the size of the audibook market is rather poor...
I can switch easily from audio to reading, e.g. listening while walking to the bus, and if I get a seat then switch to read, and then back to listening etc...