3 doctors did - the 1st, the 5th and the 10th.
The sixth Doctor's companions were Peri Brown and Melanie Bush.
Amy Pond and Rory Williams (occasionally also River Song) are the 11th Doctor's companions.
You can find a list in the Wikipedia article "Companion (Doctor Who)". Decide for yourself which ones you want to include - some were with The Doctor only briefly.
Rose Jack Martha and Donna
The Doctor's biggest enemy is the Daleks, because they led to the destruction of his home planet. He also has a very strong dislike towards the cybermen, anybody who threatens his companions and anybody who threatens his favourite race - the human race.
the most popular doctor who companions are Amelia Pond, Clara Oswald, and Rose Tyler
The Companions of Doctor Who was created in 1986.
It depends. If you count the first two K9s as two separate companions, then the first and fourth Doctors tie for 9 companions each (not counting characters who were only traveling with the Doctor for one story). Otherwise, it's the First Doctor.
The sixth Doctor's companions were Peri Brown and Melanie Bush.
The Doctor has had 29 different companions since the program's launch in 1963. There are also many other characters who may or may not be classed as 'full-time' companions.
When people die, or when people start using guns. The Doctor also gets very angry with Daleks, and when his companions are being threatened.
The Doctor's companions in 2011 will be Amy and Rory.
They have all had multiple companions, apart from the eighth Doctor in the Doctor Who movie.
The eleventh Doctor will star in The Sarah Jane Adventures along with the third Doctor's companion Jo Grant, apart from that there are no plans to bring any former companions back to Doctor Who.
The fifth Doctor (Peter Davison) traveled with three companions at once, Tegan, Nyssa and Adric from Castrovalva through to Earthshock.
In the revived series (2005 to the current series), two companions have fallen in love with the Doctor. The first is Rose Tyler (she proclaims her love for him at the end of SE2EP13: Doomsday) and the second is Martha Jones.
Yes. Most dogs are great companions! :)