Site is not fond of ad blockers, and takes significant strides for you to disable them. I disabled mine just to see what would happen, and I got 4 large moving, animated, annoying banners around the image, which moved alongside the image. Yeah, their ads are intrusive to the nth degree. There's also no promise of even non-obtrusive ads if you disable an ad blocker. Once Google Chrome's default ad blocker kicks in, I hope this site dies a horrible death. Good riddens.
A good site funded by suspicious ads and patreon donations. You aren't limited to a certain number of tags while searching and the site has plenty of quality sfw and nsfw content to browse through. The owners are very open minded about what images are put on the site so you'll find quite a few extreme images.
An imageboard which uses the Danbooru XSS layout and hosts 'hentai' a form of drawn and / or animated Japanese pornography that breaks down into many categories. Not for children. Upon visiting, Adblock Plus is required to avoid the obligatory popup to continue paying for the websites existence. Other than those flaws, Gelbooru is a good site for adults.
Gelbooru is an anime picture website. You can trust the site itself (but not the ads, imo). However, althout you can choose to browse Safe images only, chances are that you'll easily fall on adult content. So, the this site is for 18+.
This is a hentai site, and a trustworthy one as well.
But as with many adult sites, you may find what you see disturbing - learn to use tags if you intend to view it.
Keep in mind that there can be things which are illegal depending on your nation's laws - to take these out, use a "-" tag to remove them, for example "-yuri" to remove things which feature two women in it, if that would be illegal.