I voted SG-1. First of all, I never liked RDA in the show. My hope is that with the much better actor (in my opinion anyway), Ben Browder will have a chance to breathe new life into the series. My major disappointment with it is that they didn't replace any other actors! And they got rid of Claudia Black, rather than having her take up the "slot" that the Carter character should've vacated. As soon as they get special effects and some decent writers going on the continuing series, it should become excellent again.
Atlantis has yet to really *grab* my attention. S1 was hastily constructed, hastily written, and overall had very little prep time. S2 should've been much, much better, but sad to say it has not been. The Wraith aren't becoming interesting as foes, neither are the weird humans that tried to get nuclear capability. Really they're just cardboard cutouts of the goa'uld as enemies. All they end up doing is fighting the wraith, and oddly enough *winning*. They shouldn't have been.
In the meantime, until they improve the writing at the very least, they still rate below even SG-1. Which still isn't by any means my favorite scifi either. And which I will admit has gone downhill 'cause of the lack of plotlines available to them. They've had to start with a pretty much closed off and shut-down storyline.
