What hooks have you given to your players that worked ?

[gizmo33]

Curiosity (weird locked doors, NPCs doing strange things)

Greed (treasure map)

Revenge ("You see the rogue that killed your party wizard sitting in the tavern.")

Duty ("Your paladin hears rumors that a group of orcs have looted a temple of your deity in a nearby village")

Employment ("Lord Bob hires you to go get him a phoenix feather")

Alignment ("You see someone doing something evil, do you stop them?" - probably related to duty except that I consider duty something that's more specific to an organization you belong to, whereas alignment is more of a general personality thing)

I use curiosity and duty most of all. I can plan for those and predict players actions 90% of the time. Greed and revenge are the hardest to predict, I list them here more as motivators for action. When greed/revenge inspires the players/PCs, I'm usually just wing things with whatever I have prepared. If I try to use greed/revenge ahead of time, I find that the players have a different opinion of the strength of the bad guy, the risks involved in getting the treasure, etc. - that causes them to turn down the adventure.

 

[Nareau]

I can't believe nobody's mentioned the ultimate hook:
"The world will end if you don't do this thing."

I also have the players fill out a questionnaire for their PC's before each campaign. The questions essentially amount to: "What motivates you to adventure?"

Spider

 

[BiggusGeekus]

My group is increibly enthusastic. I generally don't need much in the way of hooks. This can cut both ways. I wouldn't put it past these guys to take on a beholder army blindfolded (the party blindfolded that is, not the beholders).

That said, it's always fun to borrow from The Three Musketeers...

While traveling the party comes across a man who is on the run. His clothes were once elegant, but are now ragged. He wears a satchel. He claims to be a messanger for the Queen and that he is being persued by three men in black cloaks. He does not know who these men are. He also does not know the contents of the message he is carrying. Then the men in black cloaks appear.

What's going on: the messenger is telling the truth. But the men in black cloaks are agents of the King. The king suspects his wife is cheating on him with one of the barons. The message is indeed a message of love from the queen to the baron. The black cloaked agents don't know that though. They're just to retrieve the message and deliver it to the king unread. Now the party is forced into the politics of the kingdom. They have to make a choice about who they are going to support, the king or the queen.

When I tried this on my guys ... well ... they killed everyone and destroyed all the evidence. Then they went into hiding. So we had a lot of wilderness adventures for a few sessions. So, the plot hook did work, but not in the way I originally intended.