The Asgard, Goa'uld, Nox, Ursini and Nakai are the only sentient aliens shown in physical form.
Meanwhile as relatives or creations of humans you have the Alterans, Asurans, Jaffa, Koan, Kull, Replicators and Wraith, plus the countless non-Earthling humans who make up most of the Milky Way and Pegasus galaxies.
That's a pretty short list, off the top of my head for other sentient aliens there's the Unas (re-curring, original hosts of the goa'uld), the crystal people (early episode of SG-1, goa'uld destroyed them all except one who immitated jack & came through the gate), the mushroom people (episode somewhere in SG-1, people who had a symbiotic relationship with mushrooms they live near), Sea Guy (think he was one of the "first" races, captured Daniel and made daniel remember something about Sea Guys wife.), memory guy (touches you and you remember him as a close friend/team mate you need to protect).
I forgot about the Unas, but the crystal people were just an energy race that lived in crystal, they didn't have physical form and the rest were in all probability related to humans.
OP is an account that i made yesterday, and today i forgot the pass :/, so made a new profile with a pass i can remember :p.
The original was a .flv file and i have only worked with it in .webm, since .mp* is propitiatory.
Just rip it from here or i can send a DL link if you want.