Jank is always fun, but then again I suppose it depends on how you define "jank." A deck that tries to pump out
Permeating Mass clones to turn everything on the board into a
Permeating Mass is jank.
Possibility Storm with Cascade is not jank, it's just irritating.
I enjoy trying to build around odd, niche ideas for fun. I have a Karona, the False God deck where the whole point is to suit her up with goad and "can't attack you" effects, then pillow fort up while my opponents kill each other with my commander. I have a Breya deck that is not at all tuned or competitive (but can win with a couple of infinite combos just in case the game simply has gone on way too long). Instead, I try to make as many Thopters as possible and win by punching face (did it the other day with 12 Thopter tokens and a
Hope of Ghirapur plus
Coat of Arms and
Shared Animosity). Obviously, I called it ROFLThopters. The LGS that I go to somewhat regularly on Saturdays has a casual Commander League where they will change the theme or rule set to encourage new deck designs. For example, not too long ago they did Vanguard EDH (with life total changes from the Vanguards doubled to make them actually matter in commander), a week where
any Legendary card except for lands could be your commander, and another where any commander could have one Background. Sometimes it's just as simple as, "Each player has an Emblem with, 'At the beginning of your upkeep, make a Food token.'" It's things like this that keep the game and deck building interesting.
Unfortunately, the ability to have fun with and get away with jank is heavily dependent on your playgroup and the other decks at the table. Most of the people I play with, whether it's friends or people at the LGS, tend to favor stronger decks - not quite cEDH (although they have some of those decks too), but still rather fast - looking to win before turn 8 if possible. I don't mind battlecruiser slog-fests, but my friends quickly lose interest in an EDH game if it goes longer than 30 minutes or has more than four people at the table. As a result, my decks are in a weird position where they're not good enough to be consistently competitive with those faster decks, but they're also too strong to be considered casual (except for Karona... 6 CMC commanders are a b***h to recast if commander tax applies).
All that said, I'll leave this here (MTGRemy's
I've Played Everything parody):
https://www.youtube.com/watch?v=JhFmdcbd1_A.