Add me to the recommendations for WEG D6 Star Wars.
One big advantage of the D6 system is that it is very simple, and that makes it easy to get started with, and also very easy to adapt. I've used it for both Babylon 5, and an age of sail pirate campaign.
One disadvantage of D6 Star Wars is that it was written before the Prequel Trilogy. So the Jedi rules are basically aimed at making OT Luke Skywalker, an adventurer with some force abilities added. If you want the full-powered Jedi from the prequels and sequels, you may want to look at the newer systems.
Another advantage is that, thanks to the Opend6 material WEG came up with (see
here) you can tweak and add all manner of things to fit your own particular vision.
I, for example, hacked a d6 Star Trek (complete with conversion rules for starships from the Spacedock advanced starship rules from the LUG Star Trek. Part of the hack included dropping down to just one physical stat (if you were competent physically on the shows it didn't much matter if it was due to agility or strength; lifting and acrobatics skills let you differentiate if needed), but bumped it up to five "mental" scores (piloting in Star Trek is less reflexes and more navigation and inputting of attack patterns) with an optional Psi stat and a bit of pruning of the Force powers to fit (TK is extremely rare... almost unheard of, but telepathy fairly common).
One downside to the D6 system is that's it's fairly lethal with a pretty severe death spiral and the main way to avoid it involves spending the same XP (character points) you need to improve on adding extra dice to single checks. This creates a perverse incentive where the PCs who risk the most improve much more slowly than thise who don't take risks (and therefore don't have to spend CP on boosting rolls to avoid death).
My personal house rule is just to award XP equal to the character points gained. XP can only be spent to improve skills and CP can only be used to improve rolls.