My son's first Star Wars experience. Which Trilogy First?

[Schrute Farms]

My son is five, and we are going to have our home theater set up in February (see my HT Gallery). My plan is for us to watch the Star Wars saga together for the first time and I am contemplating which is the best way to watch it.

I was born three months before Star Wars came out, and saw Empire Strikes Back in the theater on its original release date, thus I saw the OT first. I plan on watching all six films on consecutive nights and wonder if watching the OT first might confuse him once we start the PT. I bet I get a lot of "Why is Obi-Wan alive again?"-type questions, and "But I thought Palpatine was the bad guy?" etc...

My son thinks Darth Vader is really cool looking though, so the OT might keep his attention just as good as Jar-Jar. Oh CRAP, I won't be able to fast forward thru the Gungan crap this time.

So how should my son experience Star Wars for the first time?