Here you go man, best viewing order to get started. Not jumping around too much- can still watch seasons in chunks, but you're still mostly concurrent with events happening between the two seasons and movies latter on.
>01 - Stargate movie
>02 - Stargate SG-1, episodes 1.1 to 8.2
>03 - Stargate Atlantis, episodes 1.1 to 1.15
>04 - Stargate SG-1, episodes 8.3 to 8.20
>05 - Stargate Atlantis, episodes 1.16 to 2.1
>06 - Stargate SG-1, episodes 9.1 to 10.2
>07 - Stargate Atlantis, episodes 2.2 to 3.4
>08 - Stargate SG-1, episodes 10.3 to 10.12
>09 - Stargate Atlantis, episodes 3.5 to 3.19
>10 - Stargate SG-1, episodes 10.13 to 10.20
>11 - Stargate: The Ark of Truth
>12 - Stargate Atlantis, episodes 3.20 to 5.1
>13 - Stargate: Continuum
>14 - Stargate Atlantis, episodes 5.2 onwards.
>15 - Stargate Universe, All
Universe you can kind of ignore if you're not feeling it, has it's highs and lows. But absolutely do not watch Stargate Origins. Retcons have happened, but generally it was for the better to remove some of the early show stuff that they didn't really want to know where to go.
And then Origins tries to do that and does it in such a shitty, low budget way that I'd even recommend the children's tv show over that slop.