The 3rd Doctor

Spearhead from Space. The exiled Doctor has to start coming to terms with his exile and his new personality. He's introduced to UNIT properly and in particular to its first scientific adviser. Liz Shaw has a hard time coming to terms with someone who knows more than she does. The Doctor finds her scepticism wearying. We meet the Nestenes for the first time.

In The Silurians, the Doctor has the first of many disagreements with the Brigadier over the treatment of those they find themselves facing. The silurian reptiles had been masters of Earth long before mankind had eevn been a dream and they wanted their dominion back. Could they be trusted to negotiate in good faith? The Doctor thought so, but the Brigadier had other instructions.

The Ambassadors of Death. Britain's first exepition to Mars had run into trouble and as the spaceship returned there were no messages from those aboard the vessel and a rescue mission was launched, only to fall into the same trap. The Doctor and the Brigadier have to work out who is intent on destrying Britain's space programme.

In Inferno the Doctor has his first experience with an alternative universe. While supposedly helping out at a drilling rig attempting to breach the Earth's core, the Doctor is actually trying to repair his TARDIS. When it appears to work, he actually finds himself on an Earth where the Mosleyites appear to have taken over Britain.

Terror of the Autons. The Autons are back along with the Master as an ally. The Doctor is introduced to Jo Grant, his new companion.

The Mind of Evil.

The Claws of Axos. When an alien spaceship lands on Earth promising to end humanity's dependance on fossil fuels and nuclear energy, the humans don't stop to think to ask a few necessary questions.

In Colony in Space the Doctor and Jo are forced to undertake a mission for the Time Lords and meet an old enemy as well as a group of desperate colonists and ruthless miners.

The Daemons. An alien being offers the Doctor its powers after being woken by the Master but Jo puts her own mark on events. BBC 3 makes an appearance almost 40 years before its time (though the excavation would more likely to be on BBC 4 these days).

In Day of the Daleks the Doctor and Jo are involved in helping protect a Peace Conference. What no one is expecting are freedom fighters from a future that should never have happened. In their desperate attempts to destroy the man they saw as the author of their misery, the fighters come perilously close to opening the planet to domination by the daleks that rule their version of Earth.

The Curse of Peladon. Another mission for the Time Lords sees Jo being mistaken for Earth Royalty.

The Sea Devils. The Master is safely imprisoned in a specially built prison, or so we are led to believe but he's struck a deal with the prison governor and he's busily hatching schemes. Off shore, there's something strange going on near that abandoned sea fort...

The Mutants. Yet another Time Lord inspired mission sees the Doctor carrying a message to a planet that is about to be given its freedom from Earth.

The Time Monster. Atlantis gets destroyed. Yet again...
The Master pretends to be a professor working on transmat technology, but instead he's attempting to call up a chronovore in order to force the universe under his domination.

In The Three Doctors the Third Doctor is enrolled, along with his previous two incarnations, in an attempt to stop the galaxy being drained of energy. In recognition of his services, the Doctor is freed from his exile.

In Carnival of Monsters the Doctor and Jo find themselves aboard a steamship that appears to be traveling through the Indian Ocean. But things aren't quite as they seem!

Frontier in Space. Earth and Draconia are at the brink of war, a situation not helped by each side's certainty that the other's warships are attacking their freighters. But are the two powers really guilty of these attrocities? And if not, who could be behind them?

Planet of the Daleks. After being wounded by the Daleks as he made his escape in The Frontier in Space, the Third Doctor is badly hurt when he and Jo find themselves on the planet of Spiridon. When Jo goes in search of help, she's caught by a party of Thals as they attempt to destroy the dalek army hidden in the ice caves below the planet's surface.

In The Green Death an extreme case of pollution leads to something awful oozing out of an abandonded Welsh mine. Jo reckons its time to get married

In The Time Warrior, while the Doctor investigates missing scientists, someone's investigating the Doctor...
Introducing Sarah Jane Smith as the Doctor's newest companion

In Invasion of the Dinosaurs the Doctor and Sarah Jane return to the present to be confronted by dinosaurs wandering the streets of London. A traitor is uncovered in the ranks of UNIT.

Death to the Daleks.

The Monster of Peladon. The Doctor and Sarah Jane go to Peladon where the Federation is eager for the special crystals available there for their fight against Galaxy 4. But Aggador is on the warpath again and the Pels are feeling the effects of it's fury...

In Planet of the Spiders the Doctor returns a crystal to its owner and finds himself faced by a giant spider. Thanks to radiation damage, the Doctor is forced to regenerate. In whatever the antonym of good timing is (not really bad timing as such), I got the 2011 release of this on DVD just as the death of Elisabeth Sladen (Sarah Jane Smith) from cancer was announced. In an event of awe inspiring co-incidence, one of the stories you could link to on the BBC's article about Ms Sladen's death was about a recently discovered fossil of a giant spider...

In The Five Doctors the Third Doctor was abducted from his usual place in Time in an attemt to play the Game of Rassilon in Gallifrey's Death Zone.
The Third Doctor is accompanied by Sarah Jane Smith and Bessie.