I'm surprised nobody has mentioned this one yet...
My absolute favourite contest ever was the 2012 "Dream House Contest" by Cipsoft.
The contest was to describe your dream Tibia house and let your imagination loose. The winners were then picked, not only based on originality, but also how the ideas were described and how well they would work and fit in-game. The idea was so simple yet so awesome and the winning houses were added in the summer update 2012. Some of the greatest houses in the game (in my opinion) came from this contest. For example the Caveman Shelter, Old Sanctuary of God King Qjell, the Open-Air Theatre, the house of Tranquility.Here you can find all the winners of the contest: https://www.tibia.com/news/?subtopic=newsarchive&id=2041
I really hope they do a similar contest again in the future. I really like the idea of having a contest that will leave a mark in the actual world of Tibia.
I've participated in 27 fansite contests since 2014, so my experience with it is quite big :D
My favourite contests were to make Xena (mascot of TibiaMagazine) and Assassin Doll in RL. I decided to come back after 20 years to polymer clay and use it to create figurines. My Xena is still visible in TibiaMagazine's profile picture on facebook.
You know, after 5 years I think this figurine looks horrible... now I would make it much better, but because of this contest I felt like a child again and decided to improve my skills with polymer clay. It became my hobby.
Not much experience, but my faves:
* Tibiopedia.pl 2018 Ferumbras Birthday Contest [ Won 3rd place Nightmare doll ]
* TibiaEvents.com 2019 Real Weapon Contest [3rd place, Hero's medal + pirate items]
Creative contest was also TibiaEvents.com 2019 GOT TALENT, I made song from Frozen in tibia. No place, but i like it! here is video
TibiaQA fansite banner design - resultsOctober 13, 2019
Contest: TibiaQA fansite banner designSeptember 16, 2019
New TibiaQA banner chosen!October 09, 2019
How can I know where I got downvote?October 08, 2019