I often find myself searching for the same add-ons over and over. I also will sometimes be searching for an add-on and come across another that I don't need right then for that project, but that I think I might like to use in a future project.
In lieu of bookmarking in my browser or an online bookmarking service, I think it would be nice to be able to mark items as "favorites" and be able to access them later in "My Account > Favorites", or something like that.