Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

There are a near infinity of those out there, many of which just grab other scanlation groups' output and slap their ads on top of it.

Mangadex is generally my happy place, but you'll have to wander out and about for various specific mangas.

Several of the groups that post on Mangadex also have their own website and you may find more stuff there.

For example right now I've landed on asurascans.com, which has a bunch of Korean and Chinese long strips, with generally good quality translations.

The usual sticky points with all those manga sites is the ability to track where you are in a series and continue where you left off when new chapters are posted.
Even Mangadex struggles with that, their "Updates" page is the closest thing they have to doing that and it's still not very good.

If you're going to stick to one site for any length of time, and you happen to be comfortable with userscripts, Id' suggest you head over to greasyfork.org, search for the manga domain you're using, and look for scripts that might improve your binging experience there.