Super 8...I'm not really sure. Probably at least 7/10, but I probably have to think about it some. My experience was not helped by the fact that the sound at the theater was terrible. The movie was supposed to be shown in a ETX (AMC's version of IMAX) screen, but they had some issue or other and moved it to another screen, and the surround sound was barely noticeable and the center channel sounded very hollow and far away. The first 5-10 minutes were pretty difficult to even hear what characters were saying.
I will say the movie has a definite old school 80's kid/family movie (think E.T. and/or Goonies) vibe to it, but definitely a darker tone than either of those films. The kids deliver nice performances, as do some of the adults.
I think the film loses a little towards the end when the feeling of mystery and discovery fades away and it becomes a somewhat basic monster movie. There are 2 sequences in particular towards the end that felt slightly generic and somewhat out of place.
The creature's appearance is kept a mystery for much of the movie but when it is shown, it isn't all that spectacular. For me he was more of a side character though that just happened to be the driving force behind the story of the 2 lead kids and their fathers.
I think it has a chance upon further reflection (and a viewing with quality sound) to be and 8 or 9/10, but for now I'll just stick to a 7.5 with room to grow.
X-Men is still the movie to beat.