[CLB]

Both are excellent and will pay for themselves many times over.

If you're on the inexperienced side right now, then I'd say PNL should be the one you tackle first. Its very well written and easy to follow. If focuses on a few concepts, all of which are very important and if you don't already have a good grasp of them then you can probably make a significant improvement in your game immediately. If your on the more experienced side then you may find that you've already started to grasp the main concepts in PNL. Reading the book will give you some new, clearer, and more concise ways to approach them but it may not be groundbreaking stuff for you.

NLTAP covers a wider range of topics but it is definitely a tougher read. More math (EV calcs) and the like. However its an excellent strat book imo. I prefer it to PNL and think that an more advanced player (by advanced here I don't mean pro, I mean "novice player who has played a lot but still has tons to learn") will get more out of it.

I voted NLHTAP in the poll.