Both are worth a watch really. The first gig was nice because it gave a nice intro into the series and had a little bit of side tracking.
The second one however, i enjoyed it because of the introduction of a very, very good villian. just watch the frist 3 episodes of 2nd gig and you'll know who i'm talking about.
All in all, both are really good. they both have nice artistry, music & plot. If you can keep up with the techno jargon that they sling around in both gigs, then you'll enjoy this series alot.