In fact, I think I'll list my favorite three of these type of pages first:
Writers Beware
http://www.sfwa.org/beware/
Preditors & Editors
http://anotherealm.com/prededitors/
The Rumor Mill
http://www.speculations.com/rumormill/
Agent Research - a good sight, will tell you some things for free, but for a full report you'll have to pay money. (hence, a very nice place, but not my favorite. :D )
http://www.agentresearch.com
Fiction Addiction has one of the best agent lists - AAR approved and not.
http://www.fictionaddiction.net/agentsa.html
All About Literary Agents
http://www.allaboutliteraryagents.com
Association of Author's Representatives Homepage
http://www.publishersweekly.com/aar/
Authorlink Agent Directory
http://www.authorlink.com/agents.html
Guide to Literary Agents
http://mailer.fsu.edu/~tip4773/litagent.html
Lady K'Lyssia's own agent hunt:
http://imagination.klyssia.com/Ahunt.html
Literary Agency, publishers, authors, conferences, query letters.
http://www.literaryagent.net
Literary Agent Homepages
www.literaryagent.com
Literary Agents
http://www.literaryagents.org
Partial List of Fantasy Agents
http://www.ebydesigns.com/writers/fantasyagents.html
Publishers Database
www.find-a-publisher.com
Romantic Times - Romantic (genre) Agents
http://www.romantictimes.com/g_writer/g3_agent.html
The Author's Registry
http://www.authorsregistry.com/welcome.html
Writers Net
http://www.writers.net