Pacific Rim. 3 1/2 stars. Great effects, excellent fight scenes, and good acting. It's also slow to get going, the characters are cliches, and there are a bunch of issues I have with I will address in the spoilers, but overall, I did like it.
Okay, so eventually, the giant mech suits, called Jaegers, begin losing badly to the monsters, which are becoming increasingly large and tough. So the governments of the world decide to decommission them and build a giant wall around everything in the Pacific. Of course, one monster breaks through the wall in Australia will no trouble and has to be stopped by a Jaeger, rendering the entire wall project useless. Okay, so the governments of the world decide to decommission the giant robot suits in favor of a wall, which is strictly defensive, before the wall is even finished? Bullcrap. If the Jaegers were getting beaten, we'd just start developing better Jaegers. And assuming that we managed to wall off EVERY BIT OF COASTLINE IN THE PACIFIC, the wall wouldn't kill the monsters, so you'd have the issue of giant monsters roaming the ocean, effectively destroying sea travel in the Pacific. Oh, and the idea of the UN or any world government willingly turning off skyscraper size mechs is laughable.
Second, there are four Jaegers left, and in the beginning of the big fight towards the end of the second act, the two most advanced Jaegers piloted by experienced crews get torn up by two monsters with no trouble, but the main characters, who are a washed up has-been and a complete newbie, drop in in an old piece of crap Jaeger and kill the two monsters with only moderate difficulty. BULLcrap. Of course, this is because they are the main characters, so I understand why it happens, but it's still nonsensical.