I've gone back and forth in my feelings about "Scream" both times I've seen it, almost 20 years ago when it opened, and just now There are times when its meta-parody- but–still-scary approach to teen slasher films works quite well, especially the ending which manages to be funny, scary, over the top, and socially witty all at the same time. Other times it's too self conscious to actually be scary, but not surprising enough in its humor to really be as much fun as it could be.
It's also a hard film to criticize, because the answer to almost every complaint (e.g. the actors playing high school kids all look like they're well into in their 20s) can always be 'but that's the whole point, it's always that way in these movies'. But one thing that does annoy me that isn't so easily shrugged off is that the cast seem to be in a number of different movies. Skeet Ulrich, for example, brings a surprising amount of realism and depth to his character, while Courtney Cox as an 'I'll do anything for a story' reporter plays a cartoon of a cartoon. This isn't of issue of 'good' versus 'bad' acting, but it does make figuring out just what the tone of the film is, more muddy than it needs to be.
Probably the best thing about 'Scream' is it knows when to BE best. The opening and closing 15 minutes are the two strongest sections of the film, so if the middle is a little all over the place and sometimes repetitive, and a little more obvious in it's humor, that's not what you walk away remembering.