My favorite type of books I've decided, are teen coloring books. They aren't easy to find, but I found some great ones on Amazon. I like adult coloring books, but sometimes the spaces are too small and it becomes tedious to color. There are some good adult ones, but teen ones are also fun shapes! XD
I like to color with Sharpies best. Markers are just one of my favorite medias, and sharpies dry slow enough that if you color right you can get it streak free, and it' a smooth solid color. I have a lot of other markers though, including Zebra Midliners (from Japan) that are streaky but somehow I love the way it looks at the end. And Tombow has a line of watercolor markers the blend pretty well and look kinda watercolory. They aren't the best markers for looking like watercolor, but they don't tend to destroy the paper of an ordinary coloring book, which more watery markers can.
I also have colored pencils, and crayons. (Including glitter crayons) but I just don't use them as much.