I like Stargate SG-1 most, and especially the Tok'ra, but greatly prefer the way they are shown in seasons 2 and 3. What is so interesting about the Tok'ra is their dual personalities, and some time during early 4th season we stopped hearing the host or even getting the hosts name! After that, Jacob is the only one left where the host speaks. I want to hear both symbiote and host!
I don't like how the Tok'ra (and many of the other characters) are portrayed in the later seasons. Up until early 4th season, the Tok'ra seem to have been meant to be good guys and are great allies (they do continue to be good allies all through the show - giving SGC many technologies and helping Earth again and again, despite getting almost nothing in return). Later, the Tok'ra are written more and more as Goa'uld, and less and less as friends. The Tau'ri, especially O'Neill, becomes more intolerant and irritating in the later seasons as well. I thus greatly prefer the first 3 seasons and consider the later seasons to take place in an alternate universe. The way people act are simply not consistent with their earlier personalities.
I am assuming that sometime between the end of season 3 and the start of season 4, the show diverged into a parallel universe, where the rest of the show, unfortunately takes place. I think that is the only way to explain the personality changes in both the Tok'ra and the SGC personnel.
Speaking of alternate universes; I find the idea of alternate/parallel universes, time travel, and changes to the timeline to be endlessly fascinating. The episodes of Star Trek, Stargate, and other sci-fi, which deals with these concepts are often among my favorites. That is why many of my stories also deal with these ideas.