Its difficult to name a few. However here is my category-wise favorite list. (Apologies for spell mistakes if any)
Technical Powerhouses - Sancho, ptldm3, Chogy, gambhit, Antibody.
Peace ambassdors - Harpoon,butters, Imran khan,Aamir Zia.
Balanced posters - pmukherjee,Bang galore, gubbi,Desiman, Santro, Muse,Irfan Baloch,T Faz.
Nationalistic Posters- Vinod 2020, Karan 1970, Tshering, Cardsharp, Chinese Dragon. Abu Zolfiqar, Pakistani Nationalist.
Best Professor(knowledgeable and articulate) - Joe shearer
Id/Avatar with innovative thinking- urbanised greyhound.
Last but not least (no offence)
Best Entertainer - Hong Wu.
Even though everybody will admire the Contribution made by the top posters, thread starters, referrers, I want to mention a special unnoticed category of Ardent reader - genmirajborgza786 (I think he is the poster who gives most number of thanks)