HighRankings Discussion Forum Best of the Net
This has to be one of my personal favorites. You will find a wealth of search engine information and an abundance of helpful people.

Cre8asite Forums
At the Cre8asiteForums you will find information about usability, user interface, web site design, search engine optimization and marketing, and Internet law.

IHelpYouServices Discussion Forums
Have a question about search engine marketing? Not sure where to begin? You'll find many helpful people here that will to give you help and guidance. Make sure to bookmark this one.

JimWorld
Popular discussion forums for webmasters, search engine optimization consultants and Internet marketers alike. With 30,000 active members you'll find lively discussions pertaining to every aspect of Search Engine Marketing, Internet Advertising and Website Promotion, Programming, and all webmaster related subjects.

SearchGuild
SearchGuild forums focus on the discussion of search engine optimization and search engines. Very active and informative.

Webmaster World
Webmaster World wants you to think of them as part of your extended site development and process team. You'll find many interesting and informative discussions going on here. Webmaster World was a winner at the 2002 Search Engine Watch awards.