I had the pleasure of watching this film in the theater and to be quite honest that is the way it should be seen. Its a well done movie about aliens visiting earth, overall the story is nothing original (but it does have more then a few tricks up its sleeve) and is your typical Alien invader movie.
Watching this on television years later its hard to appreciate just how well this film was shot. One scene in particular involving a large dish and someone almost falling off the side of it almost caused me to make a mess in my pants when first watching the film on the big screen.
When I saw it the theater was mostly empty (not good for the movie, but it probably allowed us to enjoy it some more) and it was its first run (did it have a second?). Its sad the film didn't do as well as it should have, at the time it was the best alien related movie in theaters (I seem to remember independence day being out at the same time).
My one gripe is a somewhat weak ending (especially considering the strength of the rest of the movie). Overall it is an entertaining and somewhat thought provoking film that you won't regret watching unless you don't like movies that emphasize suspense instead of action. And there is a LOT of suspense in this film. It doesn't skimp on action either but it saves it for the end of the movie where it belongs and makes some sense.
Some people may not like its message either but I didn't have a problem with it and it certainly didn't get overly preachy. People voice their opinions on screen just as someone would do in real life, and I don't have a problem with that. The real focus of the movie is aliens, not the environment. If you fixate on the environmental message in the movie then you probably have some issues or just don't get this type of movie. Global warming is more of a subplot that leads Mr Sheen in a certain direction and nothing more.
The special effects are fairly spartan but effective and nicely creepy when they are used.
Some of the characters are kind of annoying but are necessary, and don't detract from the film overall.
A worthwhile rental, especially if you have a large TV to watch it on.