If you want a rolling release and like fedora maybe looking at rawhide. Otherwise suse tumbleweed is a solid choice.
Since you’re asking about Debian then SID is pretty much the rolling release version. This is what Ubuntu pulls from before doing their stuff. If you want close to bleeding edge this is a great way to get that rolling release feel. I know a few people who swear by it! I ran SID for a little while and it was okay but not for me. Arch was definitely better IMO for that. It’s also pretty easy to install arch (or gentoo) these days.