One of the best investments is an electric skillet. It's really good for long simmers like chili. The temperature is very adjustable so that you can, for instance, brown some pork chops, add a can of cream of something soup and some gravy master for color and simmer for an hour, turning the chops every 15 minutes. When you get that nice slow simmer going, the gravy won't stick and the meat is falling apart tender. The reason for turning every 15 minutes is mainly to make sure that the gravy isn't sticking. If it sticks at all lower the temperature a little more. Keep it covered so there's less evaporation.
A teflon electric skillet is also great for making pancakes and french toast because of the adjustable temperature and the square shape. A griddle would be nice for this, but with a small kitchen, I want my appliances to be as multi-purpose as possible.