Essentials

You can use this Plugin with or without MySQL. ;)

This plugin contains custom chat format.(You can use it or not - config)
This plugin contains custom PlayerListNames(You can use it or not - config)
This plugin contains custom Join and Quit messages(You can edit the messages in the config)

Permissions:

Essentials.* => with this permission you get all other permissions
Essentials.Heal => execute the command /Heal
Essentials.Fly => execute the command /Fly
Essentials.Feed => execute the command /Feed
Essentials.Gamemode => execute the command /Gamemode
Essentials.Inv => execute the command /Inv
Essentials.Broadcast => execute the command /broadcast
Essentials.Vanish => execute the command /Vanish
Essentials.Rain => execute the command /Rain
Essentials.Sun => execute the command /Sun
Essentials.Day => execute the command /Day
Essentials.Night => execute the command /Night
Essentials.Kill => execute the command /Kill
Essentials.Enderchest => execute the command /Enderchest
Essentials.Thunder => execute the command /Thunder
Essentials.God => execute the command /God

Essentials.Owner => for the Owner Prefix
Essentials.Admin => for the Admin Prefix
Essentials.Moderator => for the Moderator Prefix
Essentials.Developer => for the Developer Prefix
Essentials.Supporter => for The Supporter Prefix
Essentials.Youtube => for the Youtube Prefix
Essentials.VIP => for the VIP Prefix
Essentials.Player => for the Player Prefix

Commands:

/Essentials => see the help page for this plugin
/Heal => heal yourself or other
/Fly => give yourself or other player the ability to fly
/Feed => fill up your hunger or from other player
/Gamemode => change your gamemode or from other player
/Inv => see or clear the inventory from other player
/Broadcast => Broadcast a message to the whole server
/Vanish => vanish yourself or other player
/Rain => change the weather to rain
/Sun => change the weather to sun
/Day => change the server time to day
/Night => change the server time to night
/Kill => kill other player
/Suicide => kill yourself
/Enderchest => see your enderchest or from other player
/Thunder => spawn a thunder strike at your position or at the position from other player
/God => enable or disable the god mode for yourself or other player
/Home => set your home at your position and teleport to your home
/Msg => send a private message to other players
/Ping => see your ping or the ping from other players

if you still have a few ideas, feel free to write them in the comments :)