/r/HugeBoobs is, as you might imagine given the name, 100% devoted to the appearance, appreciation, love and worship of girls that have big tits. With 65,000 readers, this place has pretty much become the destination of you're into ladies that have incredible chests. It's a mixture of both professional and amateur material with images and GIFs welcome.
The current rules are that no boobs smaller than E cups are allowed, Imgur must be the host, no photoshopped tits, no personal information and no /r/GoneWild reposts. While it's only natural that chicks with bigger tits are likely to be on the chunkier side, I can actually say as a guy who prefers thinner babes that the mix is perfect. In other words, /r/HugeBoobs isn't for overweight girls that need some form of selling point. There's quite a lot of MILF material too, which I find is typically well suited for the huge boob niche - guys just love themselves a pair of big ol' mature knockers.