So i just downloaded Star Wars ep 1-6
What is the perfect order to watch them?
Depends. Would you rather watch decent action flicks, or a brilliant satire of those flicks so potent that it has 10+ scenes that give me tears and stomach pain in laughter
Just watch episode III multiple times, if you want to have the time of your life. Otherwise watch the others and maybe be interested or maybe fall asleep.
4 5 6
Don't watch any prequels
It's really that simple. You're not obligated to watch the prequels and they add nothing to the story. The only thing they do is spoil the reveals in the later episodes and give unnecessary context. Everything you need to know about the prequels is stated in the original films.
There's no order that doesn't spoil one of the films. What matters more is pacing and variety. Watching the two set-up films, the two middle films, and then the two conclusions, is a much better viewing experience. The flow is perfect, and things come across much better. Unless you've tried watching it in this order, don't tell me it doesn't work.