For Episodes I and II, I was in complete denial.

I went with IIRC six people to Ep. I. My best friend and I were the two biggest SW dorks there (which was saying something indeed) and we felt triumphant about the movie when it was over. Then the old guy in the group just started picking the movie apart, and I was annoyed with not only his buzzkilling ways, but with his accuracy. Basically, I wanted Ep. I to be good, so my blinders were on the whole time.

Needless to say, the movie did not hold up.

Ep. II had me feeling great because of where it improved above Ep. I. But again, I wanted it to be good, and I looked past all the obvious flaws.

I went into Ep. III in a much more grounded state, and I caught a lot of the problems with that particular film on my first viewing. Although the prequels de facto sucked from day one, for me the suckage was de jure after watching Ep. III.