I am unfamllar with any of those bar Shield hero and didn't see them by searching Mangadex (unless I made a mistake somewhere), what are those ones about?
Keyaruga is Kaifuku Jutsushi no Yarinaoshi. Honestly, it's edgy trash that was fun initially but gets progressively worse the longer it drags on.
Harem Labyrinth is probably Isekai Meikyuu de Harem O. It's a good erotic slice of life with believable characters. Those who choose to become slaves have rights that are enforced by magic, so it's more like hiring a live-in maid/servant.
No idea about Bunnywalker.
Isekai Maou to Shoukan Shoujo no Dorei Majutsu is a fun one where the slavery is caused by a spell backfiring instead of the usual purchase of slaves. Shenanigans ensue as a timid otaku tries to play the role of an overbearing demon king.
Mezase Gouka Kyakusen is off to a good start and the slave acquisition is suspiciously convenient. Story is meandering a bit though so I'm not sure it will continue being a good read.
Perhaps not so surprisingly, all of the other isekais with slaves on my reading list rank as decent at best. Fantasy indulgement rather than actually good stories.