The most obvious genre people think of when you talk about research and fiction is historical fiction and its sub genres. And of course that is one big Pandora's box right there. However, writers in sci-fi have to do their homework, too, so it's probably the second most thought of genre. And of course, you have research in all the other genres - mysteries, crime, and thrillers need a solid understanding of criminal justice, medical procedures, and gang cartels, drug rings...you name it. Even your contemporary work needs research - settings, character hobbies, cultural biases, etc. And let's not forget romance - that needs the same thing. And before you fantasy writers think you're off the hook, you're still going to need a lot of research too - how to world build, what elements cause social conflict, how politics and religion grow, etc. Yes, every genre has its own inbuilt research requirement.
But what impact does the research have? I hear contemporary writers cry "can't I just not mention what materials houses are made of in that area?", fantasy writers humph "but it's a made up world, I can do what I want", romance readers shout "but people are only interested in the love story", and thriller writers say "does anyone even check those things anyway - who cares if houses were made of oak in that area or not?"
While it is true you can skim, you'll be shortchanging yourself, your book, and your readers. Research is the "devil in the details". It's what gives your book that feeling of authenticity. It transports the reader into a world where the author has full authority. It is what brings a book from a story in the page, to a live world in the reader's mind. In short, it makes a book become a reality.
So, when you think of research and you groan...instead, think of how many doors you are opening to lift your novel from make-believe into reality.