There are many different kinds of markers available on the market and it can be confusing to figure out which markers are best suited to your needs and or finances. After all, it is hard to know what the differences are and if they are worth the money to purchase them. And now, with so much talk about copic markers and the price of them, it can just add to the confusion. The picture below shows a comparison of similar colors. The Prismacolor markers are on the top, and the water-based markers are on the bottom.
Water-based markers are the most common and least expensive of the different types of markers. These are what you get with Crayola, Rose Art, LePlume, and other common brands. These markers are fine for writing and for coloring for fun or if you want to be able to see your marker lines when you are done. Some have a more complete coverage than others but you will always be able to see your lines. I have spent quite a bit of money on LePlume markers in the past, and honestly have found while it is nice that they are double ended and the thinner end is wonderful for journaling, they are no better than any other water based markers.
Copic markers are alcohol-based dye markers and are great for both writing and coloring. When using them for coloring an area you will finish with a solid color with no marker lines visible. They are refillable and have a low odor. They are also cost prohibitive for most of us. They are the newest and hottest marker on the stamping sites, and are very popular as they can be blended, and even have a special blender pen available. Being as expensive as they are I have not purchased any and most likely will not. I have used them however, and they are a very good marker, and the double tips give you a wider range of ways you can use them.
Prismacolor markers are my personal favorites. They are also alcohol-based bye markers as are the Copic markers. I have heard that Prismacolor has a stronger odor than Copics. I have not noticed this. They both have an odor which you will not fine with most water-based markers, but that is due to their formulations. Having not used them both together I cannot personally say which is stronger, but I can say that neither is overpowering for me. Prismacolor gives a solid, even coverage just as the Copics do, but are not quite as cost prohibitive. They are quite a bit more expensive than water-based markers are, but I feel they are worth it, as they have wonderful coverage. They can be blended just as copics can, and also have a blending pen available.
When buying markers you need to buy the ones which are best for you and your needs. If water-based markers will work for you then that is what you should buy, or borrow some from your kids... If you want art quality markers that give you solid even coverage, then alcohol-based markers will be what you want to get. Prismacolor and Copic Markers seem to me to be about the same quality to me, but the Prismacolor markers are quite a bit less expensive.