The only anime with 'sexual' type of fanservice that I am able to watch without cringing is the already mentioned Kill la Kill. It's so overblown and purposefully hyperbolized (and affects pretty much every character at one point or the other) that after the shock of the first few episodes it very quickly devolves into something completely non-sexual. Like a literal nudist beach (ironically) - if everyone is butt naked, does it even still count?
(Excluding the whole Ragyo and her daughters bs, of course, but like I'm pretty sure that's meant to be revolting and it suceeds. Also ignoring 99% of fanart 'cause that's just rule 34 to the max.)
I used to be a pretty big Fairy Tail fan in high school, and if you watched Fairy Tail - you know it's the textbook example of the classic anime fanservice, what with Natsu constantly falling face first into Lucy's boobs or Erza's ARMORS being skimpy as a swimming suit. As a teenager I sort of tolerated it - the plot and the characters mattered more to me than an occassional cringe, but when I watched one of the newer FT movies as an adult... That particular movie was drawn in a way that made me feel like they're literally two pixels away from exposing literal ladybits and I could NOT ignore that for the sake of the plot or nostalgia. Meh.
Btw speaking of non-fanservicy anime, not sure if anyone mentioned it already, I'd say Black Lagoon counts (as long as you don't look at some of the additional manga promo art). Like, sure, there are quite some sexual topics, the women are hot and there is an occassional angle in the heat of a battlescene, but idk. To me it feels less like a "Whoops, te-hee, panty shot!" fanservice and more like, uh, adult women characters just having three-dimensional bodies, you know. They are criminal mercs, it's an adult story. But if Revy wears short ass shorts then it just feels like, you know, duh, they are in a freaking tropical seaside city, it's gotta be hot. And the whole time she spends in a skirt in that one arc she wears black leggins(?) underneath, so if the hem flips once 'cause she's doing crazy jumps while shooting people dead it doesn't feel like a typical anime skirt lift shot. Etc etc. Heck, even their characters in literal maid outfits are 1. proper scary and 2. have long skirts and properly covered up chests. Also the underage one wears shorts underneath, as she should.
Man, I love Black Lagoon, I wish more animes gave their women such badass agency with full respect.
All the other types of fanservice btw I think I fully support as long as it's not purposefully OOC. In case of said Kill la Kill I would honestly count the (SPOILER) whole switching goku uniforms plot twist as a fanservice, not the nudity. 'Cause that was definitely a lot of fanart coming through there, and if I remember correctly Trigger did literally admit to listening to the fanbase. And Black Lagoon had OVAs bringing all the classic tropes to life (school AU, genderbent AU, age-regression AU, magical girl AU...) officially. Like, this type of fanservice, when executed well, I don't mind at all.
The unnecessary panty shots and overly jiggly boobs for no other reason than 'ehehe sexy' are giving me allergies by now tho. Don't even get me started on the underage-ness of it all.