What would be the top plugins to put in a server?

there is a bunch of missing information for us to be able to help you out.... we need to know where you wan tot go with your server (ie: factions pvp creative RPG towny servival) how close to a vanilla server would you like to stay? what commands are you looking for ? but like jthomsonmain essentials is a must for any server i feel it gives you the basic commands you need to start the server with out changing a whole lot (ie: /spawn /give /tp /home /warp) things like that and it also will format your chat for you and do alot of other things you will need..... then look at the type of server you like to play on and let us know and we will see if we can help you from there.

The ones you should start off with are:
- Essentials (Basic commands, basic anti-griefing)
- GroupManager, PermissionsEX, bPermissions (Group Management Plugin)

Well... you usually just can't throw a bunch of plugins in and expect them to cooperate... plus it would be nice if you had an idea for your server... such as do you want it to be a pvp server? rpg server? minigame server?

Most basic things most servers use is Essentials.

In terms of grief prevention you have picks of Grief prevention, Factions, Towny... to name some of the popular ones.