Ok here are my few cents on the discussion. Sorry if I missed an earlier post in which this was already mentioned.
1. Don't get a weapon unless you are sure you can use it. The idea of "scare" "intimidate" or "frighten off" are all going to be very bad and end up poorly.
2. Glocks, I love them, they might not be the prettiest weapon around but they work great, field strip in seconds and are very easy to care for.
3. Taurus 1911 style pistols, I love them also, been nothing but ball peen hammer reliable for me and my friends that have them.
4. Rifle home defence gun, make sure to remember that when shooting one, they tend to have more penetration than other kinds of weapons. Make sure when you shoot one, you know what is behind the wall you are aiming at.
If I am going to recommend weapons here is what I favor. Pistol I would choose a 357 mag, 9mm, or 45 acp revolver. Sure its not a flashy but it can sit loaded and all of the springs are in a relaxed state. This means it can sit for long periods and not give the springs a memory.
If you favor an auto, make sure you rotate out the mags every so often to give the springs a rest. There are cases where mags sitting loaded for a very long time can lose some of their pressure and cause jamming.
12 gauge as previously mentioned is hard to beat. I would stick with BB size shot or around that to keep the shot penetration down some and stay away from slugs. Nothing worse to hit someone you didn't mean to because the slug went through 3 walls.
Rifle a good choice would be a lever action, because they can be loaded in sub sonic loads and loaded with soft bullets to not penetrate through to many walls (44 mag, 357 mag, etc...) You can get ar-15 style of guns also in things like 9mm, 45 ACP, 458 socom. I would stay away from things like 308 and 223 or 30-06. Again this is because the bullets from those guns might not stop for a few walls depending on what you shoot through.
