Yeah, I know this is a bit late. I like to give shows a few seasons before I start watching them. That way I don't have to cliff-hang from week to week. At least not until I catch up, anyway. I'm about midway into Torchwood's second season at the moment. The third season is a five-part miniseries ("Children of Earth"); the fourth, another miniseries ("Miracle Day"), is set to run later this year.
Available on DVD, via Netflix streaming, etc.