As some have already mentioned, I screen almost every purchase here first, unless I already trust the quality of the company (Ronin Arts, for example, has yet to disappoint me).
Books that were not at all on my radar that I bought were:
Denizens of Avadnu (Excellent book, thanks for the sale!)
Silverthornes Book of Templates Deluxe (also very good and interesting)
Bits of Darkness
Airships, by Bastion Press (Limited, but cool)
and last but not least, the reviews for Lords of Darkness, Liches and Lords of Darkness: Vampires turned me on to these EXCELLENT products from Bottled Imp Games. Sadly, this company has been in the process of withdrawing from the market, because it's great stuff. I'm very much hoping that Stuart will release Lords of Darkness:Zombies as a .pdf, seeing as how I prefer electronic over paper.