Now, I know that this may cause problems, as topics like this tend to do such a thing on forums when it comes to "opinions". I purposely didn't include the post-movie seasons, as I wanted to see which of what is often known as the "Golden Years" people would choose.
I would personally choose Season 1. I know most of my reviews (if you have read them) are positive for Season 1, and the show wouldn't make as much sense without this season, but with mediocre episodes like Sandy's Rocket/Squeaky Boots (read my review if you want to know my views on those episodes/segments) it just wasn't as good as the other two seasons.
So, which would you choose?