Tools don't make the artist; the artist makes the artist. Redundant, cheesy, but true, and it's something that I remind myself whenever I am tempted to buy another addition to my already-excessive drawing set. And although my Devious Info does note the Tools of the Trade beginning with "imagination" (and a dependence on Christ, for anything really), I still have a constantly-changing array of media and instruments that I can't do much without. As of now, they are...
1. Canson 9x12 wirebound field sketchbook with hot-pressed paper
2. 0.7mm mechanical drafting pencil with HB lead
3. Pentel Clic Erasers, if not Mars Plastic (I use both like crazy)
Below those three are items I only use on occasion; as in, I'll get them if I really want to do a serious piece, as opposed to on-the-spot ideas:
4. Strathmore 300/400-series hot-pressed Bristol board
5. Mars Lumograph pencils (B through 4H are my most-used lead hardness)
6. Wacom tablet, plus computer with GIMP 2.6 and Inkscape 0.46
7. Rapidograph technical pens (these are incredibly precise, but also very annoying to maintain)
8. 0.3mm, 0.5mm, and 0.9mm mechanical drafting pencils with HB and H lead (the smallest is great for detailing)
9. Kneaded erasers
10. 6" straightedge (anything longer is asking for transportation problems)
Of course, there are some additional tag-along requirements, like a well-lit work surface, extra lead, eraser refills, pencil sharpeners, technical pen ink, a carrying case, good music, less distractions, etc...but you knew that, right?
Any of you wish to share your top ten? I'm sure all of you have a basic toolset for sketching and a group meant for hardcore creations.