I have or had Glocks in the 19, 26, 21 (sold), and 23 flavors. All Gen 4's. I liked them all except the 21 (which felt like I was holding a brick), but my favorite hands down is my 23. Not sure why...just is. So many folks trash the 40 S&W that I guess I've developed an appreciation for it. It just shoots well for me. It is my winter (I live in S. Texas) carry gun, but the first pistol I'll grab if I hear a window break at 0200. I generally carry the 26 when out in flip flops and shorts (most of the year).
The 30 is also a good choice, if you can appreciate the feel. I cannot. I do want a .45, but that will likely be an XDm or M&P
Good luck!