Where to Find GURPS Adventures?
There are several official GURPS adventures which are published out and ready to play. You just have to buy and read them …
As mentioned above, on the page Starting with GURPS, you can download it for free. That adventure takes place in a desert area of a fantasy world.
Do you want to hunt a very big lizard in the Old West? A very, very big one? A prehistoric one, to be more precise …
Do you prefer a more classical fantasy adventure? It's intended to be played with the Dungeon Fantasy line, though.
If you want to discover what will happen after playing I Smell a Rat, the adventure given in Dungeon Fantasy RolePlaying Game boxed set, here is the next episode.
Another fantasy adventure published in Pyramid #3/98. GURPS Dungeon Fantasy 2: Dungeons, GURPS Dungeon Fantasy Monsters 1 and GURPS Dungeon Fantasy Monsters 3: Born of Myth & Magic are required to play it, though (hint by Evileeyore).
Why not rather play a team of super spies who have to save the world?
Do you like the world of Star Trek TV series and movies? Prime directive explain how to handle it with GURPS rules. That book includes a short adventure and three other ones are proposed: Planet Aldo, Starship Aldo and Dread Pirate Aldo.
But you may prefer fighting zombies ... Though not absolutely required, Zombies can help you here.
One Shot Adventures
There is also an amazing fan website where Thalcos collects all of the one-shot adventures he ran at conventions. Glance at them, they are outstandingly well written and laid out.
GURPS Adventures for the 3rd Edition