My favorite army from Fantasy literature is the Elven army, inspired mainly by JRR Tolkien's seminal "The Lord of the Rings." My favorite character was always Legolas, and incidentally, I am HIGHLY pleased with how the Elves are represented in the movie trilogy. Over the years, other fiction and gaming publications had debased them down to silly, wimpy fairies. The movies do a good job of righting that image to the fearsome warriors they were in Tolkien's works.
My army is painted to be a "Wood Elf" variety -- like Legolas' home kingdom in Mirkwood. Their main troop type is its archers, who Tolkien said could hit the "eye of a sparrow" in the dark. I also painted copious amounts of spearmen, most with various Leafs as their shield emblem. The figures are a mix of different manufacturers. A large portion are from Ral Partha 15mm Fantasy, another significant amount from the Chipco army box, which combined figs from a handful of companies.
This photo didn't come out as well as I'd hoped, but you can see the variety of poses and styles. I painted them in greens, browns and grays, so that they could "blend in" with their woodland setting.

The guys in the front, right and rear (in red) are from the Chipco boxed army. Each has their distinctive "unit" shield pattern Leaf. I came up with that idea long ago, when I painted a 25mm Ral Partha Wood Elf army (long since sold off, though), and have kept it for this army.

This is another photo it appears I overexposed. You can get a glimpse of the triangular banner which features a single tree beneath a starry sky. I picture Wood Elven cavalry as lightly armored and fighting with bows and swords. As these are the only two stands of Elven cavalry I have painted up, doubtless I'll be doing more one day.

Known in the Lord of the Rings as mighty heroes and wizards, an Elf army wouldn't be complete without these. The massively tall guy in the background is one of the Vala, or Gods of Middle Earth. In front of him is a wizard, flanked by a couple of elven heroes.

These two elven maiden warriors come mounted on top of a winged hippogriff. The figure is a 15mm Ral Partha fantasy, sadly, out of production now. I usually don't use these in my battles as they are a bit more "High Fantasy" than I prefer. I picture my elves as little more than an Ancient woodland army with just a bit of fantasy elements thrown in. They ARE cool figures, though!

I picture Wood Elves being able to summon allies from the forest to their aid -- the chief of which would be Ents, or Tree Shepherds, below. These guys are 15mm's from Black Raven Foundry and have about as much character as you could ask for. I painted them various shades of wood color, although this doesn't come out so well in this photo (which otherwise, I am quite happy with!). In "Hordes of the Things" rules, I field Ents as Behemoths (think Ancient tanks), while in Chipco's "Fantasy Rules" they become generic Small Monsters.