Every year there are gobs of books published in archaeology, so many that it's impossible to keep up. Luckily, the home pages of some of the publishers maintain a list of recent texts. This list is of reputable presses that maintain a substantial number of scientific archaeological books for the general public.
Altamira publishes a lot of paperback archaeology books, primarily on fairly technical topics.
ArchaeoPress publishes the well-regarded British Archaeological Series, as well as classics in travel and the Arabian Seminar series.
Cambridge has a broad selection of archaeology books, many academic in nature including some of the most interesting theoretical texts you can find.
The Cotsen Institute publishes several interesting monograph series, including one dedicated to California archaeology.
The CBA publishes a wide range of academic and general public monographs, for archaeologists and the general public.
Coyote Press is the place to go if you're looking for classic archaeology books that are no longer in print. They also publish a handful of related texts on the archaeology of the American west.
While not a publisher, the David Brown co is a very well established book dealer specializing in archaeology and ancient history for several small university presses.
Elsevier, who recently purchased Academic Press, has a primarily academic stable of texts, including some important archaeometry texts, regional surveys and climate-related subjects.
Just a few books on archaeology at IU Press, but they include some important field guides.
Founded by ex-archaeologist Mitch Allen, Left Coast Press covers a fairly broad variety of science topics, but the main attraction is their stable of archaeological texts, including some of the best CRM studies available.