+1 for the Aeron. I've had one for nearly 10 years and my back thanks me every single day. You can get them second hand, and if you look after them, they'll last forever.

Noodler's Ahab flex pen, Pigma Microns, Uni kuru toga 0.5mm mechanical pencil (HB or 2B Pentel Ain Stein leads, Pentel Blue leads), Pentel Pocket Brush Pen, Tombow Mono Zero Eraser, Uniball Signo white gel pen, Fabel-Castell Polychromos coloured pencils and Seawhite of Brighton Eco sketchbooks. I've probably forgotten some stuff though.

You probably already know about it, but I highly recommend Snook's book 'Scalable and Modular Architecture for CSS'. It's available at smacss.com and it's a must-read.