These are a few plugins I had in mind that I would like see supported.
OldCombatMechanics - https://dev.bukkit.org/projects/oldcombatmechanics
(Different links, same plugin) https://www.spigotmc.org/resources/oldcombatmechanics-disable-1-9-hit-cooldown.19510/
Better Book Shelfs - Store books in bookshelves. https://dev.bukkit.org/projects/better-book-shelfs
EmojiChat - Adds emojis to chat. https://dev.bukkit.org/projects/emojichat
(Different links, same plugin) https://www.spigotmc.org/resources/emojichat.50955/
Chair Plugins - Allows players to sit on stairs.
(The links below are 2 different plugins)
Better Chairs - https://www.spigotmc.org/resources/better-chairs.18705/
ChairsReloaded - https://dev.bukkit.org/projects/chairsreloaded
GTzDoors - Allows players to open double doors and multiple trap doors. They are able to knock on doors / trapdoors as well. https://www.spigotmc.org/resources/gtzdoors-double-doors-and-door-knock.37517/