A long time ago I ported TheGeek's HE-Grenade (I believe it was for v9), which he later did his own thing and I removed it, and I made a Super Mario RPG music pack. (deleted it also)
More recently, I made two or three of my own add-ons (a weapon, a jvs-content type add-on, and a vehicle) and a modeling-type tutorial. Quality is a personal opinion, but that is what I've done over the years. and I beta tested RTB twice now.