There really haven't been any worthwhile science fiction shows on TV since Stargate: Atlantis went off the air, so discovering this was a wonderful surprise. I had no idea what it was about beyond the basics, or what to expect at all, really, but once it started, I couldn't stop watching.
Humans is an extremely well done sci-fi series that, for the first time in a long time, doesn't rely on the boring, obnoxious stereotypes and tropes that plague most modern TV shows. The story is well-written and solidly developed. The characters are realistic and relatable, and their progression is believable throughout. The acting is great and very natural, and there is no cheapening of the female characters to fit some teen boy's fantasy (which seems to have become the norm for most networks, especially within this genre). Every single episode ended with me clicking straight to the next one because I just had to know what came next.
Colin Morgan in particular shines as the damaged and emotionally tortured cyborg, Leo, and the trauma of his character's life comes through in a raw, intense and beautifully heartwrenching performance that highlights just how far he's come since his Merlin days.
The only negative reviews that I've seen seem to be from MTV generation types who want everything handed to them right away and can't handle shows with a more classic feel, where the story slowly unfolds. Humans is the sort of cerebral character-driven sci-fi show that we used to get in the 90s / early 00s, not a fast-paced Hollywood style thriller, and it's perfect.
What I love most about the first season is that it's only 8 episodes long, but so much happens. The pacing isn't rushed at all and yet it packs a lot in. Things simply come together here and there, slowly, in ways that you're not expecting. I haven't been this engaged in a "real world" sci-fi series since The 4400. There's a distinct Crichton-esque feel to it and I'm looking forward to Season 2 more than anything else on TV right now.