I really liked all four of the Sinnoh movies. Darkrai's was just outright cool to see Palkia and Dialga fight and darkrai intervene, the story in Giratina's was just really good and Shaymin was great, the Arceus movie was just the coolest thing ever with the creation trio vainly fighting Arceus to protect humanity while Ash and co. went back in time, and the zoroark movie really used the illusion gimmick well and we got to see the johto legends in a movie again (first time for Raikou, finally).
The Kanto three were also really good, especially 'The Power of One'. The lucario one was great as well, in my opinion. I pretty much enjoyed every Pokemon movie bar some of the following.
The Unova movies were really bad, in my opinion. The Victini one was okay and Reshiram's voice was cool but it felt a bit repetitive, the Keldeo one was just stupid and the genesect one was the worst Pokemon movie to date. They had a perfect opportunity to bring back the mewtwo from the first movie and appeal to all the Kanto fans, which is what they were aiming for. However, they thought it a good idea to make it a different mewtwo...cuz logic. Also, the new Mewtwo was pretty weak in comparison to the original. All three felt a bit simple but I guess that's because the Unova anime was meant to be appealing to a younger audience again due to the want for a fresh start.
Just btw, I do know the proper names for all these but abbreviated them to be quick.
TL;DR: All the movies were good, especially Sinnoh's and Kanto's, but the Unova saga got increasingly terrible.