I´m surprised that someone who´s been watching anime for years would still feel so grossed out about incest themes. Tbqh the lackluster fullfillment at the end of Oreimo was worse than had they stayed together.
Staying on topic, I´d actually love to watch an anime about a successful incest relationship for once. But not one that´s all depressing or too creepy (forgot the name, but there´s this anime where a brown-haired, overweight uncle (?) gets together with his much younger niece, and it´s all presented in such a trist, painful way. Hard to watch. And kinda bad end, too. Then there´s stuff like Myself;Yourself that cops out and doesn´t properly show anything, just a quick "hey, we´re a couple now!".

My personal opinion on this topic is that incest between siblings should be okay (parent-child would obviously have an unfair power balance, so it´s a no-go for reality), so an anime should be able to portray it as something that *can* work out, too.

As for stuff that I myself find unsettling, hm. Mostly stuff I find annoying, but unsettling? Well, I guess too gruesome stuff, like when someone´s eye is pierced with a sharp tool. I cant watch shit like this.