For elves, I’ll phrase the question differently from the orc post:
What is your preferred mental image of elves, or which version of elves in folklore appeals to you?
I like John Wright’s return of elves from a higher order of being into the feared and menacing folk from ancient folk tales (from “before Tolkien and Gygax and even before Shakespeare’s A Midsummer Night’s Dream”) though, if I was to collect a miniature elf army or run a D&D campaign, my concept of elves would be the standard High Elf / Wood Elf construct. Over the years I tended to buy wood elf archers and swordsmen, which could also do duty as rangers with their green cloaks and hoods.
Out of all the stock fantasy races, elves are the one that are hardest to get a consensus on. Even Tolkien, who constructed a elven language and wasn’t afraid to include various humanoids and animals in his art, left elves out of his pictures (let me know if I’m wrong).
For me, my concept of elves is dependent on the type of fiction I am reading. I recommend Jeffro’s Appendix N as he discusses multiple authors and their concepts of elves. Beginning from the “most ancient of elves” we learn the Cornish and Welsh version were “green-haired, white-skinned sea folk” Closer to John Wright’s pagan elves there are Poul Anderson’s elves, antithetical to Christianity and unable to touch iron or bear the sight of a crucifix, while Lord Dunsany’s elves live outside of time.
Update: In the comments Deuce reminds me that Tolkien did portray elves in his art for Father Christmas. His North Pole elves and the polar bear fighting off a pre-Christmas goblin attack below:
I’ll give Peter Jackson credit for his casting of elves in the Lord of the Rings movies. Orlando Bloom was a good choice for Legolas while Elrond and Galadrial pass muster. That being said, there is a scene early in the Fellowship of the Ring in which Frodo sees the elves for the first time would change if I could. A shot from that scene is below:
That scene is really not that bad of an interpretation but always reminded me of: