Just watched Clannad season 1 with English dub. I actually enjoyed it a lot more than I thought I would. The first couple of episodes I was still considering if I liked it or not, but then I got sucked into it. My biggest complaint was the Fuko character, her storyline dragged on way too long. I felt it made the entire first season seem thin. Anyways, I will follow my usual break down.
Animation: 6/10
The animation is not the best. I guess it’s their style, it’s just kinda ugly at times, especially the faces. It was fairly consistent with its style, however.
Character Design: 6/10
This got dropped in tie to the animation. I also felt like they got lazy with the designs, the mostly changed the hair styles. I guess it’s hard to have different character designs with uniforms, BUT they could have made different body types for the different characters. I really disliked Nagisa’s hair, it looked like a mullet. And no one likes mullets 
Voices: 7/10
The voices were pretty good, only a couple of the characters really bugged me. Nothing special, however.
Story: 8/10
The story was cute, I knocked down a few points because of the Fuko storyline that went on way longer than it needed to. It does get somewhat addicting to see what happens.
Re-watch Value: 6.5/10
I could see myself re-watching this show.
Overall: 7.5/10
I enjoyed Clannad. Was it one of my favorites? No. Would I recommend it? Yes. It was cute, entertaining and has some re-watch value. Basically, just expect some comedy (sometimes even during what is meant to be serious).