The 7th Doctor

Time and the Rani. Another adventure featuring the Rani. Pity the passage of time hasn't done anything to bring her anywhere closer to her senses...
The Doctor regenerates when the TARDIS suffers a crashlanding after the Rani intercepts it.
We're introduced properly to Mel as a travelling companion.

Paradise Towers. The Doctor and Mel arrive at an apparently deserted tower block. There are people there though none are what you might call particularly normal.

Delta and the Bannermen. A tourist trip to North Wales goes a bit wrong...

Dragonfire. Mel decides she'd prefer life on the road with Glitz while Ace reckons she's had enough waiting tables on Iceworld.

Remembrance of the Daleks.Imperial and Rebel Daleks turn up on 1963 Earth to find something left behind by the First Doctor when he left. The Seventh Doctor and Ace try to make sure that the Terrans don't mess things up...

The Happiness Patrol. On Terrra Alpha, it's illegal to be unhappy...

Silver Nemesis. What was good enough for one set of enemies is more than good enough for another, as the Cybermen get a taste of the Doctor's forward planning.

The Greatest Show in the Galaxy.

Battlefield. Two UNIT brigadiers for the price of one but Lethbridge-Stewart will always be the Brigadier. The Doctor gets to be Merlin.
The Doctor and Ace intercept an emergency signal coming from Earth. But the Doctor finds himself faced with an enemy that is at least his equal.

Ghost Light. The Doctor gives Ace a chance to overcome some old fears

The Curse of Fenric. Wherin its seen that not even Ace is immune from being used by the Doctor.

Survival. The last episode of Doctor Who to grace the screens for almost two decades. Ace gets the Doctor to take her back to Perivale where she tries looking up her old colleagues only to find they have all disappeared.