There are a number of excellent markers for coloring. They range from chisel tips to fine-line markers. It is best to use them on heavier paper (as found in many of the newest adult coloring books), otherwise the colors will bleed through the page.
Sharpie and Bic make a series of markers, in both fine and ultra-fine tips. These are permanent markers,and should be used with care.
Stabilo and Staedtler markers are fine point. Staedtler has a .03 mm tip that it calls a Triplus Fineliner. I find them very useful for small areas and fine features.
Brush tip markers allow you to achieve brush-like strokes and dry very nicely. Be sure to keep the top on when not in use.
