The most recent release, Bangkok's Top 50 Street Food Stalls, is written by Chawadee Nualkhair, who also authors the blog Bangkok Glutton (an interview with the author can be seen here). The book's name is something of a misnomer, as more than half the places mentioned aren't stalls at all, but rather are shophouse-bound restaurants. The guide generally appears to be directed toward first-time visitors to Bangkok and/or cautious eaters, as many of the restaurants and stalls mentioned are the sort of 'safe' places that have long been profiled in the English-language media, and perhaps more tellingly, each entry includes a line on restrooms (sample: "squat toilet. bring your own toilet paper."). Correspondingly, the book has some good background information on Thai food for those not necessarily familiar with the cuisine (there's a particularly helpful illustrated section on Thai noodles), and I quite like the general aesthetic of the book, which emphasises lots of photos and illustrations. If you're a first-time visitor to Bangkok and are wary about eating off the beaten track (or of finding yourself in a restaurant without a bathroom), this is the guide for you. Available online or at Orchid Books.
Rather than a book, Famuluous Eateries Bangkok takes the form of 52 cards profiling everything from street stalls to restaurants. The English can be pretty bizarre (sample: "You will forget about the waiter's attitude, once you put the chicken your watering mouth..."), but the authors seemingly made an effort to go past the usual foreigner-frequented suspects, delving into many lesser-known stalls and restaurants, many located in Bangkok's suburbs. There's lots of Thai, accurate map and transport information, and I like the idea of sticking a single card in one's wallet, as opposed to lugging around an entire guidebook. If you've lived in Bangkok for a while and want to expand your culinary horizons, this is the guide for you. Available at Kinokuniya.