You could get 20 different answers from 20 different people on this. I have a G27 for concealed carry and I think the smaller models are obviously better for concealment. Maybe you want something bigger and a generation 4 with a rail if you would want to mount a light or laser for home defense. The nice things about Glocks is the magazines are interchangeable so you can buy a sub compact gun to carry and put a full size magazine in it for home defense. Decide on your caliber first then go with the smallest version would be my advice.