My rating is for the overall trilogy.
The first book in the series hooked me almost instantly. I loved Tris. Particularly, the fact that she was finding her strength and independence on her own. I really appreciated the lack of a love triangle as well. I also enjoyed Four; I thought he was strong without being overbearing or annoying.
I liked the plot as a whole. However, I did feel that it became a bit repetitive toward the end. It was not surprising to find the characters in yet another rebellion against an authority figure. It became very obvious where things were headed as new characters were revealed. As soon as David was introduced along with the Bureau I knew there would be another uprising to push things along. Even before the experiments and genetic modifications were explained I knew that something was going to be wrong and Tris and Four would have to lead another uprising. I would have like to see some more variety in the responses from the leads rather than reverting to what was already done.
I think the weak point was book two. I tend to have a hard time with the second book in trilogies so this isn't surprising. I really didn't care for it and it nearly caused me to give up on the trilogy because it did drag so much without any plot advancement. I am glad I didn't because book three was fairly good. I did think the ending dragged a bit after the climax and could have been condensed.
I was really surprised and pleased that Veronica Roth was willing to kill off a main character. That was a bold move I think. It made me like this trilogy better than the Hunger Games in some respects. I hated the ending of the Hunger Games. Tying everything up in a pretty bow just didn't fit the Katniss that we knew through the whole series and seemed forced. I am beyond happy that Veronica didn't try to force Tris into some happily ever after ending like that. It just wouldn't have fit with everything we knew about their world and the characters.
Unfortunately, Veronica started to head down that road with Four. I got really annoyed at the ending. She dies, he gets depressed enough to try to drink the Memory Serum, and then rediscovers life is worth living so he comes a.......politician? Four spent the whole book avoiding leadership until it was the only possible option. Even when he was willing to become a leader it was only because he saw no other means of accomplishing his goals if he didn't. It wasn't something he was choosing as a life goal. Suddenly, now that Tris is gone, he chooses to be politician. I know the last bits of the book were supposed to cover a few years between the climax and when all this happened but it just didn't feel genuine. And all the other characters were just glossed over: oh, peter is in Milwaukee, etc. No real explanation of the paths they have chosen.