I loved SG-1 and Atlantis, and while I did enjoy SGU it wasn't as good as the other two.
I didn't come into SG-1 until Season 7, but I quickly grew to love it. I thought the show had a great cast, and even like the cast changes over the years. Since I had only seen him for a season or two, I wasn't as attatched to Jack as a lot of people, wasn't to upset when he left. I had already watched Farscape when SG-1 brought in Browder and Black, and I thought they were great on SG-1 too.
I really loved the universe that built up over the years. I thought it really developed well, and it was nice to see a universe where they actually made drastic changes to the status quo.
I enjoyed the Ori story a lot. It wasn't as quite as good as the Gau'uld, but I still really enjoyed it.
I thought both movies were good. I've rewatched them both several times.
I did watch some of the earlier seasons over the years, and I thought that the show did change a lot over the years, but was still pretty enjoyable through most of it's run. The first season was a little rough, but that tends to be the case with most shows. I still haven't seen any of Season 6, but I plan on doing going back to a rewatch I started with Season 1 a few months ago.