Frontier is good. Ghost Game is also good. I haven't seen Appmon, so I can't speak for it, and a lot of people are 50/50 on Xros Wars/Fusion, it seems. I may be in the minority, but I find Data Squad/Savers to be... well... a child being able to hurt Digimon with punches is absurd.
XW had some great ideas but poor execution i feel. It picked up around ep 14 or so and started to get good. The 3rd part was a mess of course arbitrarily adding rules without any clear reason. I just wish they had done better at explaining why suddenly in part 3 you cant just combine 4+ digimon all on your own. Like sure part 1 and 2 were i the digital world and part 3 was not but they jsut go "Hey these are how it works" could of been nice if they said that it was due to not being in the digital world or something.
Savers was fun, and yeah Masaru punching shit was silly at first but hey it made sense. More so in savers with the term Digisoul- he was able to basically cloak his fist in a energy field of some sort. The fact that the dub replaced Digisoul with "Digimon Natural Ability" or DNA made it really odd "Use your DNA to punch"
But yeah masaru was head strong he was the type who thought you could fix anything or solve any problem by hitting it, and if that didn't work, hit it harder. And sometimes it more or less felt like his Digisoul reacted more to protect him from hurting himself- than to hurt the enemy mon. But wrapping your fist in what equates to a energy shield and slamming that energy shield into an enemy well makes sense that it'd cause some damage.