I know it's hard to get started, so here are some concepts to get the creative juices flowing. Just little prompts, to give you your own little plot bunnies.

Tavern in the forest- This has to be the basic plot everyone has seen once in a while. Can't really call it a plot, even. The basic idea is that travellers are travelling through a forest, and meet at this inn, and the characters just interact and make their own plot from there. Since this concept is more of a setting, it has endless possibilities attached to it.

War-  Kingdom X versus Kingdom Y. Another basic one, with whatever reason you like behind the conflict. This one's open for action right from the start. War can also be between noble houses, or a civil war.

_____ vs. _____ - Fill in the blanks, and oh look, a plot. Humans vs. magicals. Peasants vs. nobles. Good vs. evil, there's a classic one.

Uprising- Tyrant on the throne? Gather a rebellion and go kick some evil !

Overcoming an evil- This could be the local madman, or the aftermath of something which happened. Recovery and coming to terms with events can lead to interesting conclusions.

Good mage, bad mage- Conflicting personalities like the good and the bad can lead to clashes of power, authority and morals, even the clashing of weapons. In this case, mages hold a power other than physical, and keeping dark mages at bay can sometimes prove challenging. Mages as power figures prove to be interesting positions, more often than not.

Assassinated/kidnapped monarchy-  This falls under the rebellion category, but the bad type. Often jealousy of other figureheads leads to this. The characters could be the kidnappers/assassins, breaking in for their target, or the characters could be there to stop the event from ever taking place (tip-offs, anyone?)

Bandits- Oh, this is a good one. So much can be done with this, it is one of my favourites. This concept includes robbing nobles, stealing things with hidden power, "Robin Hood" situations, a heist gone wrong, bandits ambushed by the local authorities (the Guard, as they're called around the interwebs usually)... And so on. Bandits are great. Just sayin'.

Pest problem- This has vast potential for what exactly the pest is. It could be insects, rodents, or the local dragon come out to play. In fact, it could be a clan or guild of cut-purses annoying the nobles. Animals could be breaking in to houses for jewellery.

Daemon issue- Having a daemon take over a person is always a problem, because the usual daemon plan is "kill everybody, then take over the remaining world". Not a great plan on their part, but they spend centuries in the spirit realm waiting for their chance, and when they possess a mortal, they go all out.

Artifacts of power- This is a great one. Ever come across cool stuff in the backstreet markets? Well, in a world of fantasy, who knows what they can do, and what kinds of trouble they can get someone in.

Famine- Who doesn't love a good disease? One with a rare remedy, which needs to be found in that hostile part of the kingdome nobody likes. Yeah, that one.

Quest- This is a more basic concept, but also one with huge room for development and imagination. Pick a journey the group of characters have to make, a reason behind it, and some obstacles. It makes for an awesome journey.

Natural disaster- This one can happen in most settings, so whichever natural disaster you fancy, you can pick your setting from that, or vice versa. Not a very chipper subject for the fluffy writer, though.

_____ gone wrong- You can put almost anything in the space. Things go wrong, no matter how good or greedy the intent, no matter how perfect the strategy used to do whatever they might be doing.

Arcane wonders- Any spiritual appearances recently? An entity trying to tell us something? Any apparitions, or mysterious sightings? Magic can be a wondrous thing, and doesn't have to be channelled through a being. It can be just another wonder of the world. So... what mystical things happen in yours, and are they benevolent or malevolent?

Provings- Remember, not all plots are doom and gloom. Some are a positive mood, including the provings. These are when warriors battle to become knights within the King's court. The public love a good proving match, and often things are happening on the side.

Festivals- A nice celebration of a recent victory is always fun. Or even, just an annual celebration of the changing seasons, or the harvest festival.

 Had an idea? Great! I did while writing this, by the way, so I hope it does the same for you. These plot concepts can be good to mix and match, as well.