Links:
Japanese game import FAQ, information pages, and forums in English:
PC-Engine Catalog Project Cover scans to all PC-Engine games, tons of PC-E info
Insert Credit News/info page on Japanese and obscure US games
The Magic Box Lots of information about upcoming JPN games for all systems
Namako Team Keeps a decent linklog of recent JPN videogame info
NFG Games Hardware, tech, x68000, videogame obscurities (and more!)
Hardcore Gaming 101 A nice collection of articles about lots of series of games.
Honest Gamers Mix of old and new, us and jpn, computer and videogames
Dreamcast History Covers US and JPN games (Unfortunately they gave up on updating the released games list a few years ago)
Game FAQs Decent source for FAQs on US or Japanese games
NeoGAF gaming forums (More US than Japanese game topics, but lots of conversation on both)
The Next Level Gaming Forums
..and while Youtube is a horribly mainstream site, it is a way to see footage from games you don't know about if you just do a search for them
Videogame related pages in Japanese:
Falcom home page Home page of my favorite Japanese videogame company (in Japanese)
Super Famicom Data Complete Japanese catalog of Super Famicom games
Anime-related pages:
Anime On DVD Information on US releases of anime
Anime News Network Another US-anime release information page