A post apocalyptic drama without zombies is a nice break. Made by the Lost crew, it has that stranded on a desert island feeling but the island is the ex-USA and all the power has been turned off. Even the whiney little kids grow up quickly and stop annoying you. It is only one season in at this point but well worth the watch.
A bad girl who witnesses the suicide by train of a woman who looks exactly like her, takes on the dead woman's life and all its complications. This is not your typical American sci-fi drama and that could be because it is mostly Canadian. I watched the entire first season on the edge of my couch. If you watch nothing else on this list, watch this.
This honestly is one of the dorkiest sci-fi series I have ever watched but I can't help but love it. It is very formulaic and often predictable but the characters make up for it. The acting does improve over the seasons and so do the story lines. Guest appearances from the greats of sci-fi TV from Bionic Woman, Torchwood, Battlestar Galactica, Firefly, Star Trek: TNG & Voyager and even Warehouse's sister series Eureka, to name a few. If you love all sci-fi TV then this is your show.
Those are my top 3. Get on it!