• SHREDDER! - My ultimate favorite. I actually own one at home. There's just something so satisfying about watching this office supply at work and hearing its buzzing, shredding sound.
• Stapler - Every now and then I get stapler-happy and staple scrap papers for fun.
• Whiteboard (with marker and eraser) - For doodling!
• Sharpener - Using a sharpener makes me feel like I'm back in kindergarten. And I love seeing all my pencils sharpened.
• Cutter (with steel ruler and cutting mat) - It makes me feel in control over things.
• Sticker labels/CD marker - Labelling things = addicting.

Runners-up:

• Foldback clip - One of my most prized possessions in college. I used foldback clips to fasten my readings together.
• Highlighter - For highlighting must-watch movies on my TV guide, haha.
• Masking tape - A real savior during emergency situations.
• Paperclip - It's always fun to make different shapes out of them.
• Double-sided tape - Just because.
• Blu-tack - Everything sticks! Amazing.