I love a lot of the appmon designs, outside of the Super grades. I feel like making them “chibi” was a pretty big mistake. As far as overall favorite, I love Roleplaymon, and I wish there were more RPG appmon.
You know what? I'd really have to think about this. Let me go look at them again and see. The main cast was cool. ...And I just realized that I don't remember many female Appmon except for the obvious.
Team Fakemon; he was an overly dramatic dumbass of a character (aka great all around) and the design is just lovely. The tiny Trump Swords on him are absolutely adorable too, I love the tribute. Charismon was absolutely dope too, that guy looked so cool. (Also while we didn't see him in the show, that one Appmon who just looks like a chibi version of Ancient Wisemon is cool too, as well as the recycled Appmon version of Garbemon)
I like Offmon for his cuteness - but I feel he's not a great partner to Yuujin personally. So in terms of partner Appmon, my favorites are Gatchmon and Hackmon because of how they stick by their partners who go through some of the darkest moments. In terms of general ones, I rather like Navimon and Roleplaymon. I would like to see Navimon used more often with GPS type Appmon who are a threat.