I love to see what tools other artists use. Here is my arsenal.
From top to bottom:
My handy little pencil case, the col erase non-photo blue pencil, Staedtler lead holder, .05 mechanical pencil, Staedtler Mars plastic eraser, Speedball Super Black India Ink, Faber-Castell Pitt artist pens (S,F,M,B), Royal Clear Choice Brush, Hunt 107 crow quill pen nib and holder, a kneaded eraser, and my hardcover sketch book.
I have a few faves of the bunch. The mechanical pencil is great for really tight pencilling. The Pitt pens use waterproof India ink. I love the Pitt brush pen especially. I enjoy inking with a brush but it's just not feasible for sketching on the go. This brush pen gives you the great line variation, waterproof India ink, and its easy to carry. I also can't live without the kneaded eraser. It takes off soft lead without a trace. Same goes for the eraser pen. I don't like the sketchbook because its heavy and I've broken the binding without much effort. However, the paper is of good quality and has a nice smooth finish with nice tooth.