Salvation was worse than I expected by far, though still better than T3. It's been a while since I saw it so I don't remember precisely what things I decided didn't make sense with the plot, besides not knowing where the humans were still able to get enough fuel from to power their jets and helicopters, or why all of those years after the nuclear holocaust of Judgment Day, things were STILL on fire... stuff like that gets to me.
As for the rest of the series...
T1 was pretty good, minus the choppy claymation-like animation of the T-800 at the end, although I understand that was the limits of their technology par their budget at the time. B+
T2 was excellent, nuff said. A+
T3 was, like Xenu mentioned, came off as a parody of the series. Lots of cheesy lines and I couldn't buy the whole thing about the miracle nanobots that can let the TX control vehicles that can't have the mechanics to accept remote control, or that the TX was stupid and transformed back into its true form while walking toward its target while camouflaged as its fiancee, or how even though it's designed to destroy other terminators, decided not to terminate the good T-800 but rather re-program it, and even then it utterly failed at that simple task. I could go on and on about why I want to punch everyone who made that movie possible. F-
And yeah, T4 could've been a lot better, at least it made few enough references to T3 such that I could pretend that movie didn't exist. C.
And the Sarah Conner Chronicles, they were okay. I was never quite sure how or if they'd ever fit into the movie series, and was disappointed how they were always teasing us with all of those near-misses where they'd almost stumble upon what the audience already knew but kept dragging it out until the end of the 2nd season or so, and now apparently the series is canceled so I dunno, made the whole thing so pointless. C+.