I'd like to suggest some interesting superlative categories
Greatest Lost Treasure: no longer available because it was lost in the Great Hacking, hosted on an inactive site, or otherwise been lost. (hopefully a short list!)
Most Spectacular Failure: had great potential or interest but was never completed.
Most Inspirational: has produced the most derivatives, variations, or imitations.
Best Niche Creation: very well done but only applicable to a very specific purpose.
Most Revolutionary: noteworthy not necessarily for its own popularity, but for opening up a new direction for others to follow.
Most Saved Time: A utility, tutorial, or template that has saved the most effort by automating or simplifying a process.
Most Distinctive: universally recognized at a glance, and everyone knows who made it.
Best Prank: was made as a joke, and became unexpectedly popular
Most Technically Impressive: took the greatest skill and dedication to get right, even if it's not readily apparent (graphics, programming, or mod-making)
Best First: a particularly impressive creation for a first attempt
Most Tragically Overlooked: great work that for whatever reason just didn't catch on
Most Downloaded or
Longest Thread per Graphic/Mod/Tool: More of an honorable mention, since it's an objective measure.
And a few personal achievements:
Polymath: for significant contribution to the community in multiple categories
Master Craftsman: for mastery of a particular category
Supporting Actor: valued not for what they create, but for what they post- whether it be encouragement, research, record-keeping, debugging, or technical knowledge
Founding Father: influential in the early days but no longer around
Powers That Be: For best contribution to the community in their role as a moderator (this could be a touchy one

)