I agree with you on the last couple of seasons. I think it had to do with RDA. He was getting tired... I consider this a new season 1 for Sg1...
That is heresy. O'Neill is the greatest, but don't blame Anderson for getting tired of the weekly series grind. He did it for 8 years on macGyver and 8 on SG1.
I love SG1, but just started watching it this year. I purchased quite few DVD's of earlier seasons.
I have Firefly on DVD. It's easy to find (Amazon) I got it for Xmas tho.