The machete order is the best way to watch them.
http://www.nomachetejuggling.com/2011/11/11/the-star-wars-saga-suggested-viewing-order/
A friend of mine and I recently did a marathon using that order and it really does enhance the story, and even improves the (2) prequels. It's a really long post about it, but interesting and definitely the way to go.
I also recomend Adawyn's "Star Wars Revisited" version of "a new hope" as the ideal edit of the original movie. (And man do I wish he would get empire done).
This was the first time I've actually read about the machete order. The article was extremely well written and once my youngest son, Lando, is old enough, I'll introduce him this way. My first 2 I went in release order.