People

Companions

Rose Tyler

Captain Jack Harkness

Sarah-Jane Smith

Adric

K-9

Tegan Jovanka

Nyssa of Traken

Ace

Turlough

Romana I

Romana II

Doctor Who Companions

UNIT (United Nations Intelligence Taskforce)

(Apparently you can't use the full title - I've read that Russell T Davies has said in the new DWM that the United Nations don't want to be associated with it!!!)

Brigadier Alastair Gordon Lethbridge-Stewart

Captain Mike Yates

Sergeant Benton

Surgeon Lieutenant Harry Sullivan - Travelled with the Doctor and Sarah Jane Smith in the TARDIS

Elizabeth "Liz" Shaw - the Doctor's replacement as UNIT's scientific advisor. She became his assistant when he returned to Earth.

Jo Grant - her uncle used his influence to assign her to UNIT

"Famous" TARDIS Travelers

Adversaries

The Master (see Master write up under Time Lords)

The Rani