I like the hot pink, lime green, and sky blue folders. $3.99 for a pack of 6. Have to buy individual colors, which is what I like.
Letter-Size Hanging File Folders - $6.99 for package of 6. If you get the desktop file box, you'll want hanging file folders for inside.
The Container Store > Landscape Letter Tray $9.99
$27.99 The Container Store > Bristol Desktop File the two side by side will fit perfectly in the cubby of an Expedit, so we can get rid of our ugly file cabinet - finally
To use instead of a filing cabinet (just put them on a bookshelf)? A bin for credit card/financials, taxes, etc.