I watched this 'I am legend' recently, and I liked it. It is as close to SciFi as I have seen (apart from the aha films like Matrix etc...). After watching these Red Planets and AVPs etc..., this movie came as a welcome surprise for me. The storyline and the near-future-ness of the movie, set it apart from those. Ok, what is shown in the movie:

1. Cancer cure (feasible near-future)
2. A virus that eats cancerous cells and keeps a check on Cancer (again, feasible)
3. The virus mutates and infects under UV rays (feasible, ok).
4. The virus infects and increases the metabolism rate, forcing people to do more activity (perfectly reasonable).
5. Only some survive the effect, others die (ok, may be feasible)
6. Those folks, affected by the virus, have to do stuff at a greater rate, to survive. Their brains are useless to satisfy their instinct, which probably asks them to rip each other apart. (perfectly plausible). In order to satisfy their instincts, they stopped using brains and acting like civilized humans.

In a sentence, they are suffering from infection. This is not like those movies where, people die and become zombies. And somehow, the virus re-animates them (Very unlikely). Also, it is not like those entirely imaginative movies like, alien technologies (god knows what is the Science in showing those as SciFi), and Matrix type movies (which are great to watch, but, entirely imaginative more or less)

As an aside, the main point of Matrix story is slightly un-justified. If machines are taking energy from us, and making us live life through a program, so be it, many people would say. As the humans are living a life anyway, what is the point of trying to change it, and come to "reality" etc... Did machines kill folks, no. Did they torture us, no. All they want is our body heat, as per the movie. At least they didn't even hint about machines ditching us, and moving to an alternate power source.

This movie revolves around the near-future that gives great satisfaction to view it, and feel the idea in it. Everything in the movie is close to future, and relevant to the contemporary setting (be it social, humanity etc...). I would truly recommend it as a SciFi movie. In my opinion, SciFi movies are better that way, having an angle relevant to contemporary things, and showing somewhat imaginative (believable) SciFi. And, I liked the humanity/social angle in it as well.

There's another movie about 'human cloning' and using the clones to replace the organs of folks, who insured them (essentially killing the clones). It is called 'The island' and I liked that as well. It is contemporary and believable SciFi.