I have went through a beautiful time in sitepoint, thus I want to know are there some other similar forums? I want forums that do follow and with signatures.
I don’t think there are any other forums, are there? 
But seriously, I doubt there’s much link juice from signatures, even if they are do-follow. Forum posting is perhaps useful for getting noticed, but I doubt it’s worth using them for backlinks.
It’s true signature weighs less in current days, but it’s also true that it’s better to get one than no at all.
[FONT=Verdana]There is a thread here, listing other forums to which SitePoint members also belong. Visit some of them and see what you think.
However, because of the number of people joining up simply to drop spammy links to their sites, almost all the reputable forums have been forced to adopt the same policy as SitePoint and make links nofollow. And as ralph.m has already pointed out, even where this is not the case, the number of links on a page will dilute the “link juice” to a level where it’s pretty much worthless.
Forget about looking for forum links and find a more productive way to spend your time. :)[/FONT]
Do follow forums are hard to find these days. I heard about startupnation.com before, maybe you can check it out.