At this point, I am going to issue a spoiler warning. It's impossible to talk about Catching Fire without giving away some of the stuff from The Hunger Games. I may also be ruining some cool stuff about Catching Fire, so if you don't want to know, please stop reading now.
I'm going to say that I was disappointed with Catching Fire right from the start. The way The Hunger Games ended led me to believe Catching Fire would take place immediately after The Hunger Games. It didn't. Catching Fire took place months after The Hunger Games, leaving out a lot of the things I wanted to read about (most importantly Katniss's homecoming and reunion with her family and Gale). But no, it skips ahead to her tour with Peeta halfway between their Hunger Games and the next one.
Once I got over that though, I was pulled in by the story. The Capitol's President appears in person at the beginning of the tour to issue Katniss a dangerous ultimatum: she must convince the entire country that her feelings for Peeta are genuine or else those she is closest to will die. After the events of the previous book, several of the Districts are beginning to rebel, and they are using her act of defiance (and the unprecedented two champions of the 74th Hunger Games) as their symbol of rebellion.
So Katniss tries her best, but it isn't enough. The Districts start rebelling, leading to harsher conditions back in her home District (even though the people have not rebelled there). Gale is severely punished, after which they lose access to the woods. And then the unthinkable happens: for the 75th Hunger Games, the candidates will come from the living winners of previous Hunger Games. And in Katniss's District, there are only three. And only one of them is female.
Catching Fire was a pretty good story, even after my initial disappointment. There's a lot going on, and you can really tell that it's an important turning point for not only Katniss but her entire world. But that being said, I don't think Catching Fire was as good as The Hunger Games.
So now I'm onto Mockingjay, the final book in the series, tomorrow. I'm really hoping it will be a great ending to the trilogy. And I'm hoping that this time, Mockingjay will take place immediately after Catching Fire's story ended.