I watched the first episode and whilst I wasn't sure initially about the acting and special effects (probably because I'm so used to the films), the story itself was very interesting and I liked how it was unfolding. After the second episode I was hooked. The episodes are well written and offer more information as to the history of skynet, old and new characters and this all links in nicely to The Terminator 1 and 2.
I have always been a bit dubious about films that have been made into series as, expect for one or two (most notably Buffy the Vampire Slayer and Stargate), they have mostly been awful. You only have to look at the Blade or Robocop series to see what I mean. When I saw an advert for Terminator: The Sarah Connor Chronicles, although it looked quite interesting, I was again worried. Fortunately it delivers enough in every department to keep you interested.
Credit has to be given to the main cast as they are well suited to the characters they play, Summer Glau in particular is very enjoyable to watch playing the sexy terminatrix (which even beats in Terminator 3). Thomas Decker also really impresses as the young John Connor and comes into his own around episode 7. Sarah Connor takes a bit of getting used to after the role being so well played by Linda Hamilton, however she also is really good in the role.
I think that generally it could have been even better, but as a first series and for a film franchise in particular, this has been a well made series which will hopefully get even better in the future. The next series has already been given the green light so I'm looking forward to that already.
The special effects for TV Series are also good, although they aren't in the same league as bigger TV series like Heroes (first series at least) or Star Trek, this is evident in the scenes of the future where the weapons don't look anywhere near as good (when fired) as the films. The Terminators themselves also don't look quite as good as in the films, but are still very realistic.
In some ways this is better than the third film, whilst in others it isn't. If you liked Terminator 3: Rise of the Machines then you will probably enjoy this and even if you didn't there is enough here to make you watch it. Regardless of these facts the series is worth a look and making up your own mind as it adds to the original story as well as developing other areas further. It will be interesting to see where it goes in the future.