I've run Ostarine, s4, and Im running s23 now. Also cardarine and sr9009.
Ostarine- I liked it alot. Used it for a recomp, good strength gains. Nothing dramatic but a nice little compound.
S4- Loved it. Didnt really get vision sides and good awesome strength gains. Also helped great while cutting.
osta/s4- ran em together and was obviously the best. They compliment each other perfectly. Its my favorite stack so far
Cardarine- Not a sarm. But its amazing for cardio. I dont think it helps directly with fat loss, but allows you to do endless cardio which obv leads to fat loss
Sr9009- I liked it. Its similar to cardarine, maybe a little weaker. And with its short half life and sketchy bio availbility, I'd stick with GW (cardarine)