I love doing research for my stories, mainly because I love learning new stuff.
So far working on The Emergency Coven and its characters led me to taking a Swedish language course at University, doing research over different Wiccan traditions (which eventually came in handy for another unrelated work of mine), Maori culture and words, British/Swedish/NY/Philadelphia/NZ slang, health-related stuff (how burns "age", what can commonly cause asthma, how Tourette's syndrome exactly works) and a whole lot of legal stuff, including but not limited to "how much does an ambulance cost in the US", "how does adoption work in Egypt", "how to press a charge and how is murder punished in the US", "how does dual nationality work" and so on and so forth. I'm not from the US myself, and although I'm familiar with a lot of the culture thanks to having friends and family living there/movies/the media in general, I constantly find myself wondering if I got things right. A lot of what I research doesn't even make it into the story, but I like to make sure I'm not getting things wrong at least.
Also, athough I can't promise to give a 100% accurate representation of the town I chose as my main setting (in part because I've never seen it with my own eyes and mistakes might always happen and in part for story reasons + not wanting to offend anyone by putting stuff like real sacred places in a fantasy/horror story, so a bunch of names will be made-up), I still spent quite a lot of time looking at the real thing on Google Street view, did some research on its story and I'm going to mention some of its landmarks in the comic.
I also don't like it when research is inaccurate or blatantly wrong, especially when it comes to historical settings... truth to be told, bad research in historical novels is what usually makes me prefer historical non-fiction to novels most of the time
I tend to be more forgiving when it comes to other genres, unless the mistake is SO BLATANT that I simply can't ignore it. I remember this one fantasy author I used to love as a kid being criticized to hell and back because of her "unrealistic fights", but truth to be told, I found the criticism in that case to be excessively nit-picky, as most of the things that were being criticized were stuff only a medieval weapon expert would know. On the other hand, I almost noped the hell out of that one Buffy The Vampire Slayer episode in which a bunch of "Italian" characters speak such an awful Italian that not even I, an Italian native speaker, could understand what the hell they were saying love the series, but damn, that was bad, and no, it wasn't just the pronunciation, but everything else as well XD