I have a good one that wasn't me, though I've told this before in here.
In my last place of work, bullying was rampant and one particular year was shit especially for my colleague (we'll call him Chris) who essentially had been micro managed and picked on by former friend and now-manager Keith. Chris was a really hard worker and so lovely and in the midst of a spending cut spree, they did that thing where they treat everyone like shit in the hope they'll walk before they're pushed.
Chris had been hugely over worked for no extra money or TOIL, and in a time where, after 6 years of IVF, his wife was finally pregnant, he was bullied by Keith into missing antenatal appointments because "this is an important deadline" all for him to say "oh yeah the deadline was actually tomorrow I just didn't want you missing it". Chris was on the verge of a nervous breakdown by Christmas
So Chris and Keith got each other in the secret Santa. Chris, because he was a good person, bought Keith a bottle of his favourite whisky. On the present opening day, Keith said "Oh shit I totally forgot" ran out to Tesco next door, came back with a 4 pack of Special Brew and gave it to Chris.
Chris put the whiskey bag away, said "Oh I got you too, let me just nip to the car for it" and went to Tesco, and bought 16 bags of Tesco value dried pasta. Handed the bags over and said in front of everyone "Here you go Keith, cheap value pasta for a cheap value boss". Then passed me the whiskey bottle and said "here you go Glummy got something for you too". I was so proud
Keith was clearly raving but didn't dare say anything.
Luckily both Chris and I got new jobs after that but remain close and still talk about the furious look on Keith's face when he opened the Tesco bags 