Taking a quick break from work to chime in:
Orphan Black is better by miles and miles. And it doesn't just appeal to a female audience. My husband LOVES Orphan Black, more than I do, for the intricate plotting and how well the "clone interaction" is handled from a technical perspective. I like it for the characters; it still catches me off-guard sometimes, how much I like one clone more than the other, and how can forget that they are all played by the same person.
Orphan Black is good right from the start and stays good. Falling Skies has some really good moments, but by the time you get to season 3, it starts sliding downhill at an alarming speed. Season 4 was fairly horrible. It still has good moments but that's all it has--a good MOMENT, here and there, instead a good season.
^ JD, season 2 of Orphan Black is just as good, if not better, than season 1.
Orphan Black is on season 3 and I'm still liking it quite a lot.