Here's a good one from another site:
OK, so I have a bit of a background as a graphic designer...my co-worker/target has been trying desperately to get me back for wrapping his cubicle in tissue paper (see "Covering for my co-worker" in Office Pranks)...but he's not very original...he keeps doing stupid ---- like taping my mouse ball down, or gluing my ruler to my desk.
I decided enough was enough, I was tired of the stupid pranks...I bought a Tim Horton's coupon book...they're a donut and coffee shop in Canada, in case you're wondering. I went home, and did a simple scan of it on my computer. Then, I tweaked it out a bit, and put in that he will receive a dozen donuts, and 6 large beverages of his choice, as part of a promotion at our workplace (we have a Tim Horton's right downstairs)
To ensure he wasn't suspicious, I printed off 6 of these coupons, and left one on all the desks in our section of the office. (My other co-workers were in on it) I had one of them, Jen, tell the target that she used hers yesterday, and that it was his turn to get coffee and donuts for everyone...he was away on Monday, so he didn't know any better. So, he asked me to come down with him, to help carry it all up (how perfect!)
We went down to Tim Hortons, and waited in line...the line-ups can be quite long first thing in the morning, as you can imagine. Well, after about 15 minutes of waiting, we finally made our way up to the counter. He went into great detail about which donuts he wanted in the box, and even what each of the coffees should have in them. It wasn't until after the poor counter girl got everything together that he presented her with the "coupon"! She stood there for a minute, looking at the paper, and finally, went into the back to get her manager. The manager came out, and looking rather disgusted, told my co-worker that this coupon was a fake, and that Tim Horton's would NOT honour it! You should have SEEN the look on his face! There were about 30 people standing in line behind us, many of them commenting on the guy who was trying to rip off Tom Hortons!!! I couldn't help myself...I burst into laughter.
I felt so high from my prank that I didn't mind buying the coffee and donuts for us! I've gotten many many congerats on the success of the prank...many from the very people who were behind us at the coffee counter!
Let me know what you think...not very original, I know...but highly effective!!! I'm eagerly awaiting his "revenge"