Firstly, there are two basic types of color films I'll go over. Then I'll go through the brands and lines of film that I have used. In the image above, I have two sheets of 4x5" film sitting on my light table. The one on the left is a color positive (also called a transparency or slide) and the one on the right is a color negative (also called print film). As you can see, they are quite different.

Positive film gives you an image the way you saw it when you snapped the shutter. It also produces rich, saturated colors and strong contrast. Due to these characteristics, it is very important that the exposure is perfect when using positive film. There is not much room for error, overexposed areas will quickly become completely white and unusable, underexposed areas will be very dark or even black and only recoverable with some very expensive scanning equipment, if it can be done at all. When using positive films, it's important that the scene not be too contrasty, or that it be controlled using graduated neutral density filters. However, when the scene is just right for positive films you get rewarded with fantastic colors. This type of film is also typically easier to scan and work with digitally.

Negative film looks like an orange mess when viewed on a light table, with only very saturated colors showing up as odd purple and cyan tones. It is meant to be inverted during the scanning or optical printing process to get the correct colors. This film creates softer, more natural colors and lower contrast than positive films, allowing for a much greater latitude with exposure and dynamic range. Highlights in the scene are usually handled wonderfully and these films can take quite a bit of overexposure. They tend to require a little more care when scanning to get the colors to match what you remember when you took the photo. It will typically appear too cyan for my taste and need some corrections. Now on to specific lines of film, starting with positive films: