Let the beating of the dead horse begin.....:
A shotgun is the best choice, as already pointed out. My choice would be a Mossberg 500 or 590, again, already been pointed out. Any good pump action will do, as will any good semi-auto shotgun. If a guy could find a good side-by-side doublebarrel with exposed hammers, it would be a primo choice, too, though limited in capacity.
A rifle might not be a bad choice either, especially one chambered for a handgun cartridge. A lever gun in .357 Mag, .44 Mag, or .45 Colt would be a great choice for a couple of reasons. Rifles are generally easier to shoot well than are handguns. Even a .30-30 rifle would work, though I'd be leery of that. A pump-action rifle would be good here, too, and some are available in pistol calibers (IMI Timberwolf, anyone?). Ruger makes a carbine available in 9mm and .40 S&W that uses the same magazines as the Ruger semi-auto pistols, and would make a good companion for them.
If you insist on a handgun, a double-action revolver would be the weapon of choice, keeping in mind that your primary concern is home defense. Any good 4-6" .357 Mag loaded with anything from standard pressure .38 Special on up will do just fine. A .44 Mag/Special loaded with good .44 Special defensive ammo would do well, too. In either of these chamberings or a handgun in .45 Colt, you can double it up with your rifle and use the same ammunition for both. Revolvers require a minimum amount of maintenance (one of your requirements) and can sit forever without springs weakening while loaded.
If you prefer a semi-automatic, any good double-action or double-action only pistol will work, though I wouldn't recommend one given your criteria.
Now, you say "I need help choosing my first firearm. This gun's main purpose is for defense. I want a basic gun that works and does not break easily. Something reliable enough for infrequent use. I do not want anything too fancy, just something that will enable me to protect me and my family from would be attackers. Thanks so much for your time." Most folks here are probably taking that to mean that you have never shot before (inexperienced shooter). If this is the case, get a good .22 rifle and/or revolver and practice with it until you are comfortable before buying your defensive weapon. The .22 will be better than nothing until then, though far from ideal. If you've shot before and just don't have any guns of your own (experienced shooter), then you're ready to jump right in and can follow the advice of others. The consensus seems to be "A good shotgun is best, a good revolver is suitable." There are so many options in between that it would take days to write up all of the options and the pros and cons of each. Ultimately, it's up to you and you should get what you're comfortable with.
