I am looking for some good advice on the best guidebook for Thailand... I have seen good and bad reviews for Lonely Planet, Lets Go, Rough Guides, and Footprints....please help! Thanks.

They all have their good points and bad points.

The Lonely Planet book is excellent, the bad point is that one quadzillion of other people carry it, making for backpacker congestion. I have used it.

Though not as respected, I found the Lets Go! Thailand book to be pretty damn good, much better than anyone knows, and carried by almost nobody.

Somebody will come along momentarily to suggest the Footprint or Rough Guide, but in my opinion, they are all pretty good.