Eldar Guardians

I like the guardians, but according to eldar fluff, I have a hard time using them. If the race is on the path to extinction, I wouldn't send partly trained, weak armored civilians into battle. They are good for sticking to your objective in the backfield, but usually get hosed down pretty quickly when on the front line. I usually use large squads of them, and hope the other player has better targets to shoot at.

One time they did end up driving off and running down a squad of genestealers, much to the surprise of the hive mind controller! (granted the genestealers all attacked some harlequins who were in the melee, but the guardians did win the battle and ran them down.)

Eldar Storm Guardians

The eldar storm guardians are some of the most underated troops in the eldar codex. I love dropping these guys off out of a waveserpent, toasting whoever is on an objective with their flamers and a warlock with destructor, and then taking the objective after the barbecue is done. Most of the time people won't worry about 10 storm guardians in a waveserpent, until it is too late. These guys are also great counter-attack troops when supported by an aspect or harlequins.