General
Digitalpoint
One of the best forum in the web.Here discussion related to search engines, including optimization, marketing, tools and other technical aspects.
Offtopic
Offtopic is not specific to any topic it covers technology,entertainment,lifestyle
and more.Registeration is required for this site.
Somethingawful
Somethingawful is also a best forum site.It has totally 145,068 users, 79,591,800 archived posts and strict forum rules.
Skyscrapercity
Programming
Oracle Forums
It is one of best forum site for java,j2ee and sun products related questions.Sun forum site is now migrated into Oracle Forums site.
Stackoverflow
It is a programming Question and answers site that’s free completely and no registration required.Stack overflow is aspects of Wikis, Blogs, Forums, and Digg/Reddit.
Codeproject
Code Project was formed with intention of provide developers with a place to meet and exchange ideas.It covers C#,ASP.NET,C++,Java and almost all programming related questions we can discuss here.
Java Ranch
Java ranch is a friendly place for java programmers.Here you will get everything about java,j2ee and related software’s doubts.
Operating Systems
Linuxquestions – This forums is mainly for your Linux operating system related questions.
Ubuntuforums -
This forums is mainly for your Ubuntu operating system related questions.
SEO
SeoChat
This forum is about search engine optimization.Here we can discuss about Keywords,link building and how to improve page rank..etc.