Random URLs For The Win

http://hkaityo.hp.infoseek.co.jp/dq/index.html
A Japanese page with monster sprites from Famicom and Super Famicom installments in the Megami Tensei series, along with those from some other games like Romancing SaGa 1-3. Warning: in Japanese.

http://dbz.icequake.net/share/afs/pub/emu/nesnew/www.theredeye.net/index.html
TheRedEye's site, saved from the brink of infinity.

http://rpg-home.lunar-net.com/choose.htm
Animated GIFs and illustrated walkthroughs for the Phantasy Star, Shining Force, and Lunar series.

http://www.roempire.com/database/?page=monsters&act=list
A list of EVERY monster on Ragnarok Online, including thier animations.

http://www.pekori.jp/~emonoya/monster/index.html
An impressive collection of monster images from a myraid of Wizardry games on various formats. Warning: also in Japanese.

http://www.tenchionline.com/ragey/Shinobi/main.htm
The Super Shinobi 2 Beta Central.