[ikue]

I would say the Design of Everyday Things by Don Norman. I've also heard but haven't read yet Don't Make Me Think by Steve Krug is really good too.

[samwillis]

While "the Design of Everyday Things" is as close as you can get to a bible for ergonomics, and design for human interaction, it was published in 1988. It is absolutely worth reading, it will make you a better designer, however it will not give you insight into "modern UX design".

[ikue]

There was an updated version put out in 2013. I read it a couple years ago and it's helped me plenty.

[samwillis]

Gosh, I did not know that. I read it in about 2005/06, will have to purchase a new copy!