>>44395952Koga's Gym was pretty neat, the invisible (although not quite if you look at the floor) walls was a pretty novel concept and I kinda wish it made a return. In HGSS Bugsy's Gym was pretty cool with the whole Spider Switch puzzle also Morty's Gym in HGSS fitted pretty well and was a pretty novel concept.
Wallace's Ice Breaking Gym is pretty cool and one of the few times I think the series actually had a decent puzzle to it, Winona's Gym puzzle idea was also cool but the execution was underwhelming. Crasher Wake's Water Level Gym is probably the best Water-Type Gym in the series although the aesthetic of it is pretty garish, Candice has the best Ice-Type Gym though, it builds on what Pryce's Gym had done before but doesn't dumb it down like Brycen's Gym in the following generation.
BW has no cool gyms, B2W2 has almost entirely cool gyms, the only not particularly interesting ones are Cheren's Gym which is just and I get that it's Normal-Type but that's hardly an excuse for a bad gym, also Elesa's Gym was kinda eh since the idea of battling all the Gym Trainers to get to the Gym Leader was already done with Roxie's Gym and I'd argue the execution was better with Roxie since each Gym Trainer was clearly assigned to an instrument. Rest of the B2W2 Gyms are solid favourites are Burgh and Clay's.
XY had some interesting ideas, funnily enough they are probably the only generation to actually make good use of 3D with stuff like Grant, Viola and Ramos' Gyms. Olympia's Gym and Wulfric's Gyms are honestly pretty great. Out of the SMUSUM Trials I can't really say any of them are good, the closest to good was the USUM Sophocles' Trial simply because it had an actual puzzle to it, Gen VII sucked for this sort of thing.
Wooloo Herding if it was made more complex would've been a truly great gym, Kabu's Gym is pretty cool as is the idea of Opal's Gym although the execution could've been cooler (have it have more variety like the Battle Arcade).