Maggie, paneling does come in about a gazillion different colors and styles. Many are real wood. Many are pictures of wood on vinyl. Many are all sorts of wallpaper-like looks on vinyl.
The best and most expensive is prefinished sheets of thick (1/2" or more). The cheapest is 1/4" with the vinyl overlay. There were stores that specialized in just paneling but these are about a thing of the past. We have rooms done with both kinds and the cheap kind can be false economy. The den, done with the expensive stuff, still looks great and the basement rooms done with the cheap stuff is pretty beaten up. 4 kids will do that.
If you don't hang it yourself, installation cost is about the same for either. If you do install it yourself, the thicker is easier to hang. I have to admit that I was pretty nervous about cutting $40 sheets 20 years ago and they are probably a lot more now. You can buy a good power circular saw and plywood blade for less than the cost of installation and have some left to rent a miter saw for the trim. By the way, the manufacturers make special molding and trim to match their wallpaperlike designs.
One other issue is that you want to choose a light colored paneling, or at least a couple of steps lighter than you think you want, if you go with a wood look. The darker the color, the smaller the room will look. Refinishing can be done down the road but it is usually a big chore. It is almost impossible to refinish to a lighter color but it can be done. When you look at cost, interior paint is good for seven years or less. You have to patch holes, wash, prime and apply 2 coats of paint. All of this has a time and material cost. Good paneling lasts at least 20 years. I'll tell you how long when ours starts to look bad. It hasn't happened yet.