Note that, since all of the sites are forums, you are likely to find the same freebies repeated all over. You will, however, find some new ones on each forums. None of these forums require registration to view topics/threads.
NsaneForums
TipRadar
Tipradar forums requires registration to view external links on threads. The site offers its own giveaways and runs contests as well. It is loaded with other useful contents besides giveaways.
MalwareTips
MalwareTips is a security based forum where users talk about different malwares & viruses, how to remove them and also about different antivirus programs, and the ways to troubleshoot their problems. So, most of the giveaways here are related to antiviruses and data security programs.
TweakBytes
Along with external giveaways, the site also runs its own giveaways and contests. It is a fairly new site with very less number of members. However, the site does contain some new freebies that have not been mentioned on other forums.
FreeKaaMaal Forums
FreeKaaMaal is an Indian bargain hunting website where you can find coupons and items with heavy discount. The discussion forum of the site is where the users share deals and offers. The freebies section is divided into a sub-section of International Freebies, which makes it even more easier for international users to find free offers.
These are the five forums for freebies. If you know any other source of good freebies, comment below to let us know.