This is a list of released and unreleased accessories for the Virtual Boy:

Released accessories:
Nintendo Adapter Set
Performance Adapter Set
Adapter
Adapter Tap
Headphones
Soft Carrycase
Hard Carrycase
The following are actually replacement parts for the VB, but can also be seen as extra accessories:
Eyeshade
Eyeshade Holder
Stand
Controller
Battery Box
Protective Game Cover

Unreleased accessories:
Virtual Boy GameLink® Cable no picture, help!
Rechargeable Battery Adapter no info/picture, help!
Adjustable Stand
Soft Eyeshade
Shoulder Harness

Here are some (not officially) released Virtual Boy units/accessories:
Small Size JPN Demo Unit
Small Size USA Demo Unit
Medium Size Demo Unit
Big Size Demo Unit beware: many pictures!
3D VB Logo Light
Tradeshow Demo Unit
Prototype Unit
TV Display Device no picture, help!
VB Development Kit
VB ROM Vending Machine no picture, help!

MISC items:
Promo VB items:

Baseball Hat Red & Black
Baseball Hat Black
Baseball Hat Purple & Black
Baseball Hat Black & Purple
Big 3D VB Promo Pinback
Small Hudson Soft Pin
Non-3D Pin
Store Display Cards beware: big pictures!
Japanese Store Display Cards
American T-shirt Red & Blue
American T-shirt Red no picture, help!
Japanese T-shirt With VB Icon
Vest with VB Logo's
Store vinyl banner
Japanese Promo Poster
Japanese Promo Cards
Special 3D VB Glasses
Special 3D Cards + Glasses
Virtual Boy buckle up key chain no info/picture, help!
Battery-operated Digital Desk Travel Alarm Clock With VB Logo in bag w/intructions no info/picture, help!
Sunglasses with "Virtual Boy" emblazoned on temples no info/picture, help!
V-Tetris Mechanic Toy
NOA VB Magazine Promotional Slides
Laser Disks With Nintendo VB Promos + Ads

VB boxes:
American System Box beware: many pictures!
Japanese System Box beware: many pictures!
Japanese Special Edition System Box
Japanese Special Edition Adapter Tap Box
American Store Copy Of System Box
American & Japanese Display Plain White System Box
Japanese Display System Box
Japanese Game Delivery (Factory) Boxes
American Mario’s Tennis Display Box
Japanese Store Game Display Boxes