Eh, personally the mons I like usually end up being being a coalition of numerous things. After all, my favorites list has many reasons, ranging between:
"I use this guy in competitive and has saved my butt many times!"
"I used this guy in a playthrough and came pretty clutch!"
"I like this fella's role in the game's story!" "I like this one's design! They're cute/badass!"
Or simply
"I just think they're neat!"
Not all of my favorites qualify to all those categories at the same, but I don't think it matters much. Variety is the spice of life after all! And personally, I just find having a single universal criteria to find favorites kind of boring. That's just my opinion though.
"I use this guy in competitive and has saved my butt many times!"
"I used this guy in a playthrough and came pretty clutch!"
"I like this fella's role in the game's story!" "I like this one's design! They're cute/badass!"
Or simply
"I just think they're neat!"
Not all of my favorites qualify to all those categories at the same, but I don't think it matters much. Variety is the spice of life after all! And personally, I just find having a single universal criteria to find favorites kind of boring. That's just my opinion though.