This month's review subject is located at http://www.rifts-rpg.com, and is, oddly enough, a site devoted to Palladium's Rifts roleplaying game. It is also the largest, most in-depth Rift's site I've ever seen.
Given that I am a die-hard Rifts fan, I'll break my vow of laziness and say a few words on it. Rifts is a futuristic, post-apocalyptic roleplaying game that takes place on Earth and combines aspects of magic, mythology, science and future technology. Besides the main book, and the conversion book, most of the Rifts world is split up between books, usually by country, continent, or dimension. The rules are relatively simple, useful, and expandable. I really like commas. The greatest thing about the game is its flexibility. I recommend that everyone give it a shot, you won't be disappointed.
Anyway, this site has a ton of sections. There are advanced rules, a nice FAQ, campaign material, monster/magic/equipment/psionics references. There's even a gaming (mostly Rifts specific) humor section. Even if you're not a Rifts player, check this out. It may make the difference between an average and a good roleplaying game for you.