It might be a minority view, but I loved Jonas Quinn's character! Why? Because he made Teal'c a fully fledged [/edit] character. The both of them interacted so well. Teal'c was part of the main cast since episode one, but he never felt like a real person with their own emotions until season 6.
Christopher Judge is an incredible actor, but until Corin Nemec came along he wasn't allowed to be a whole person with their own agenda. Even small stuff, like not sharing his ice cream in "Prometheus" / "Unnatural Selection", would have been unthinkable before Jonas came along.
I think, retrospectively, telling Jonas to fuck off be with his people when Daniel came back hurt the series in the long run. Corin was a good actor, and Jonas was a good character.
I always really enjoyed Jonas too. When he first arrived I really missed Daniel Jackson, but I missed Jonas more when he was gone than I ever did Daniel.
I also liked Jonas Quinn, but it took a second rewatch to get over the guy wrenching despair I endured at Daniel’s death/ascension. Absolutely gutted me, I was too mad to enjoy Jonas after that. But after the second time I agree, Teal’c became more with him than he did when Daniel was part of the team. Part of me wonders if it was intentional on the writers part, like “oh we have this big gap where character was, let’s fill it with two characters instead of just replacing one”? Or if it was just kind of naturally their interactions were more fluid.
I fell in love with Daniel in the theatrical movie, and I was upset when he left the show. And Jonas just felt so incredibly disrespectful, like they were trying to insert a Daniel clone into this raw empty space. I really hated that. If they'd given him some other specialty, made him a different physical type, something. But they didn't, and I hated Jonas.
I wished Jonas was utilized better after season 6. Obviously the return of Michael Shanks trumps Corin, but Jonas was such a fresh character that help push the exposition along.
However, if you look at Corin Nemec's twitter account, the dude is a bit of a nutjob.