Really hard, I love series 4’s soundtrack,

But series 5 has I am the doctor

And series 9 has the shepherds boy.

I really love these. Series 4's soundtrack was really fun. My favorite composition is The Shepherd's Boy, though, so Series 9 for me.

Series 3! It has The Doctor Forever, All the Strange Strange Creatures, Martha's Theme, The Master Vanglorious and We Will Remember Them just to name a few.

But out of these options:

1. Series 4

2. Series 1

3. Series 9

4. Series 5