I never read the comment section of any video, or news article. Most people have legit no clue what they are talking about. I actually learned that from Reddit. The number of times you go into the comment section, and see the top comment is full of shit is staggering. This is usually about politics and other stuff though.

In terms of product review, it honestly depends on the product I'm looking for if it's something non-tech I will usually just take whatever has a decent rating-to-price ratio. If it is highly technical, then I usually have to consult a lot more than just the reviews, ratings, and critics. For example I did extensive research on all things involving computer components, before I built my first tower. I knew the essentials of every piece and why spending a hundred to two hundred dollars on what people considered "non-essential" or "high-end" was actually worth it for the amount of life you can get out of those components.

Rotten Tomatoes I have to say I often look to. In my defense I will say that if the critic score is shitty, but the audience rating is high I will still see a movie.