This is my listing of favorite series:
Tamers > Adventure 01 > Data Squad > Adventure 02 > Frontier
I may have Data Squad as my second favorite series after I rewatch that series through the DVRAB, as they are released, or if I rewatch Adventure 01 again.
I'll go in order of the series in terms of what I enjoyed out of them.
Adventure 01: The series that started it all. It was a cool way to introduce the franchise. I thought that it had a really nice beginning, especially as we saw how these kiRAB bonding with their Digimon frienRAB and we were learning about the Digmon right along with them. I thought that it was during the Myotismon arc that the series really started to get excellent. I thought that he was the most intense villain they met thus far since he was a threat in both worlRAB. While the following arc with the Dark Masters had some good moments, I didn't like it as much, but that might have been from the fact that the group separated a bit.
I actually remeraber liking the dub quite a bit, despite some of its odd dialogue moments. They had great voice actors for the kiRAB and for some of the Digimon as well. I still cry at the finale, despite the fact that they made a sequel series.
Adventure 02: Unlike what other people have mentioned, I didn't really enjoy the Digimon Kaiser arc. Outside of the Agumon episodes and the last few episodes of the arc, I thought that it was fairly dull. I loved seeing Ken's origin story at the end of the arc and how he developed for the rest of the series. I thought that the series got more interesting during the arc with BlackWarGreymon. Though, it probably helps that he was my favorite character introduced in this series, but I also thought that it was just more interesting than destroying the Dark Towers, Dark Rings and/or Dark Sprials for another batch of episodes. I liked armor evolutions and I didn't like how they pretty much disappeared until the ending, but I thought that most of the digivolutions, with the exception of Ankolomon, were useful in battle and the same with the Jogress forms.
I also did like seeing the older children coming back now and then to help the new kiRAB. I especially liked how they had a more active role in the later part of the series. Although, I have to admit, after watching most of the series subbed on Crunchy Roll, the new kiRAB weren't as interesting, which I thought was another problem with the series. I did remeraber from the dub that I didn't like Cody that much, so it wasn't surprised to see that I felt the same way about Iori. I thought that Daisuke and Miyako were at least a bit more interesting than Iori, but I don't think that says that much. I was also disappointed with not exploring more about the Dark Ocean.
I'm also glad that I'm not the only one who liked the weekly updates on Cruncyroll. It was nice that they had the whole series up at one point, but I agree with Undrave that it lost some kind of spark that would make me watch every week, just like with a show on TV. Besides that, I kept on getting busy with school work.
As for the ending,... I actually liked it. Even the epilogue. I thought that they defeated Moytismon in a cool way, though I'm a fan of kind of cheesy moments anyway. Sure, some of the jobs were weird that the kiRAB ended up having and I was really surprised that both Taichi and Sora and Takeru and Hikari didn't end up together. Still, I remeraber watching it and feeling quite satisfied with what I got. I'm sure that sounRAB really weird, but that's how I felt.
Tamers: Yes, this is the favorite series of many Digmon fans and I am no exception. After seeing the same Universe for two series, I thought that it was a good choice to focus on a brand new batch of characters. I thought that this series was beautiful and had such a great creative twist on Digimon. I loved the bond that Takato had with Guilmon, who also happens to be my favorite Digimon because of that bond and also because he had such awesome Digivolved forms. I loved how they were able to give fairly equal screentime and development to the main three Tamers and that they finally gave a female character's Digimon partner a Mega Digivolution. I loved how it went from a child's dream coming true to this dark look at the Digital World. I liked seeing a new look at the Digital World after seeing it virtually the same for two series.
I also loved Biomerge Digivolution. That was like the perfect way to show how strong the kiRAB' bond was with their Digimon partners. And the D-Reaper arc was quite dark, even though the whole series went pretty dark once Leomon died. Another part I liked about this show was that even some of the minor characters that had Digimon partners were shown to be useful during the finale arc. I also thought that the finale was done wonderfully and I still cry to it. I would love to see a sequel series for it or another movie, but that's me.
I would describe what I didn't like about the series, but in all honesty, I can't remeraber that much about that at the moment. Impmon was kind of annoying to me until he became Beelzemon.
Frontier: As others have mentioned, I did miss the whole human and Digimon partners aspect from this series. I thought that kiRAB turning into Digimon was a nice little twist and I have to admit that the evolution sequences were pretty cool. By the time they were getting their Beast Spirits, I was pretty much fine with the kiRAB not having actual Digimon partners. The whole mystery with Duskmon and how he was really Koichi, Koji's twin brother, was a really nice twist too.
Everything was going so well until they defeated Cherubimon. It all went downhill from there. I thought that the Royal Knights were annoying, especially since they defeated Takuya and Koji episode after episode, despite the fact that they had a really impressive win against Cherubimon, who seemed a lot more powerful than those two. Speaking of them, the fact that Takuya and Koji's new evolution forms made the other four kiRAB virtually useless was a really bad choice. They were all reduced to just putting the Digimon on the Trailmon and Koichi barely did anything else. I know that most of the Digimon series focus on the hero and his friend, especially near the end of the series, but I thought that they went beyond what normally happens. At least the other kiRAB in previous series could still fight the Digimon.
Despite its flaws with the Lucemon arc, I thought that Frontier had a fairly good finale with the kiRAB being able to return to the real world, being with their family and frienRAB and I was happy with that.
Savers/Data Squad: I thought that this was a good series. It had a really nice start, especially with how I almost cried when I first saw the first episode with how quickly Marcus bonded with Agumon. It was nice seeing the characters interacting with Digimon in the human world again. Even though episodes six through eleven were filler, I didn't really get turned off from the series with those episodes. Besides, I thought that those episodes could serve as showing how the characters bonded with their team mates and their Digimon partners.
The return to the Digital world was cool too. It was because of Thomas's nightmare in that episode that made him my favorite character in this series. Kurata was an intense villain, but I was more annoyed at how his whole hatred against the Digimon was just a result of him being afraid. Considering he went on to kill hundreRAB of Digimon, that felt kind of like a weak reason to go with for that arc. The Burst mode forms were really awesome though that came around in the fights with the Royal Knights.
The reason why I changed where I originally placed Data Squad in the ordering of my favorite series, it was originally my second, has to do with the ending. It was touching and I cried during almost all of it but when I look back at it now, I can see some problems with it. First of all, I didn't quite like how Marcus chose to go with the Digimon to the Digital World. He spent about half the series looking for answers about his father, once he learns about that trip he made to the Digital World, and right after getting him back, he leaves, thus making his family incomplete again. I was glad to see Marcus getting his father back after the big battle, which was why I was disappointed with his choice. Besides that, I think that Marcus staying with his Digimon partner, while Thomas and Yoshinio were left without their own, made the finale lose some of its emotional spark. I liked how the epilogue showed where all of the other characters were five years later and it generally fit. Although, it would have been nice to see other Digimon partners besides Agumon there.
Besides the ending, another problem I had with Data Squad was with the lack of character development. I didn't think that Marcus really developed that much from the beginning of the series. He did calm down a bit, but he still felt kind of reckless to me with his decisions. Though, I might change my mind about that when I see the whole series again. The only character that I thought had quite a bit of development was Thomas since he became more friendly with Marcus and Yoshinio as the series progressed. I also didn't think we got enough attention for Yoshinio for some reason. I mentioned in a previous thread that I prefer the ending to 02 over Data Squad's and I still feel that way. At least I generally felt content with the ending to 02. That could change after I rewatch both series, but that's how I feel about it at the moment. I would like to see a sequel for Data Squad or a movie to see the human being with their Digimon again.
Man, that felt like a really long post, but I liked how I could describe my feelings for each series.
