Terminator was very good.
Terminator 2: Judgement Day was a masterpiece, I still love to watch it today.
Terminator 3: Rise Of The Machines was decent in my opinion.
Terminator Salvation was... (we don't talk about that one)
Terminator Genisys was... ok.
Terminator: Dark Fate was a very weird clusterf*cked roller coaster ride, meh it's ok.
They should've left it after 2, they didn't need to make further films that only exist as a cash grab and serve to taint the franchise more than it adds to it.
PS: The Sarah Connor Chronicles was utter trash.