I'm surprised no one has started a thread about this yet!
Just got done watching Pacific Rim, (husband surprised me straight out of work with tickets, isn't that romantic?), and I had a fantastic time with that movie. I'll be the first to admit that I'm a huge Del Toro fan, but even I was a bit skeptical how this one would play out.
It was awesome. Amazing effects, a great world and premise, and a side story that was straight up the most engaging side story I have ever seen in a sci-fi movie, hands-down. The dialogue was a bit cheesy at times, but it was so forgivable with everything that was going on. Also, Ron Perlman. Oh, and Charlie Day. Those two are scene stealers.
On the visuals, you just need to see it. It is really neat how much of the set and parts of the monsters are actually built and not CG'ed.
Overall, solid piece of cinema! Del Toro can do no wrong!