Hi Julius, it often depends on what kind of writing you do. Because I normally work in the spec fiction space I’ve found that the SF Online Writer’s Workshop is an amazing place to get feedback from your peers. It is also often visited by agents. Here’s a link: http://sff.onlinewritingworkshop.com/ (note this is a paid forum, but for me it’s worth the small outlay, which is tax deductible if you’re a professional writer). Hope that helps.