I watched Lockout last night (6.1 IMDB), and I couldn't really fault it.
All of the sci-fi gadgets were spot on and well designed - just the right amount of believable progressive technological adaptions that may happen that far into the future.
The plot was fairly water tight, apart from the space dementia thing, which was obviously shoe-horned in for the importance of a certain part of the plot - but for the sake of an action sci-fi, I was happy to wave this.
Some funny one-liners; sexy male and female stars; enemy with just the right amount of nastiness / comical value ratio, and I pretty clever wist in the tail.
Worth a watch imo.