According to my Records Stats screen...
Jigglypuff is my Favourite Character and Bowser Jr. is my Second-Favourite Character.
(Mii Gunner is my Loneliest.)
For Records Offline & Battle Arenas, my Play Time is as follows...
-
Jigglypuff (86:06)
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Bowser Jr. (LUDWIG) (80:24)
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King Bowser (75:24)
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Pokmon Trainer (29:29)
-
Little Mac (16:51)
As for Records Online, my Play Time is...
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Jigglypuff (77:43)
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Bowser Jr. (LUDWIG) (69:18)
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Lord Bowser (60:14)
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Pokmon Trainer (41:49)
-
Mii Brawler (Team Rocket Grunt Ludwig) (20:24)
Clearly
if I had to pick two mains it'd be Jigglypuff first, Ludwig second, and Master Bowser third. <.<