Thermal media is the easiest to write on with a marker. 
Ink pens, specifically ball points** and extra/ultra fine tip type markers, are engineered to release ink at a flow and pace equal to human writing speed. When you write too fast, you'll notice the ink is thinner or entirely missing. If you write too slow, ink pools on the paper, and your writing looks sloppy.
The so-called "fine" point markers, all the way up to the large "fat head" markers, tend to drool ink pretty quickly. If you write fast, it looks great. If you write somewhat slower (as I tend to do), you'll get continuous ink pooling as you write, leaving you with "fat writing" that can close loops and generally make your writing illegible.
Now that's all based on "normal" writing paper and most standard writing surfaces.
Inkjet surfaces, however, are engineered to absorb ink. So when you try to write with a pen, or extra/ultra fine point marker, it sucks in the ink right out of the pen. The writing will look as if your pen was giving out, even if it was new and full. You have to learn to write slow enough to give the ink time to replenish itself at the head, but without allowing it time to pool. The "fat" style markers still tend to pool, even with inkjet media, unless you're writing very quickly and lightly.
Thermal media has a "normal" type of writing surface, which is why it can be easier for a good marker.
These are great Sharpie markers:
http://www.amazon.com/gp/redirect.ht...reative=390957
And then note that
you do NOT need "DVD safe" markers.
And welcome to digitalFAQ.com -- feel free to ask more questions, if you need anything else. Thanks.
** Important note:
NEVER use a ball point pen on a disc!!!
The mention of a ball point was for informational purposes only, to aid in understanding of how a pen works!!!
