Glock 26, I shoot that better than any of the other Glocks that I own. Its easy to conceal, shoot and is 100% reliable. I really like the Glock 43 due to the ease of pocket and appendix carry. It is also ver accurate and 100% reliable. I would have a touch time saying one of these is my favorite, because they are both my favorite for different reasons. I always carry one or both of them.
I've owned almost every Glock made over the years but none now. Probably liked a 34 the best but it doesn't hold a candle to my Sig 320 or my Sig 226 Legion.
I carry a Glock 23 2nd gen, but my favorite is the Glock 21 (have 4) and one is on a Mech Tech CCU which is my home defense carbine. The 45 acp in the Mech Tech has almost no recoil and is very quiet to shoot.