Certainly, here are some possible completions for the sentence "My best friend ________________":
1. My best friend loves to play guitar.
2. My best friend and I enjoy hiking together.
3. My best friend is always there for me.
4. My best friend has a great sense of humor.
5. My best friend and I have known each other since kindergarten.
6. My best friend's favorite hobby is reading.
7. My best friend and I share many interests.
You can choose a completion that fits the context you have in mind or create your own based on your best friend's characteristics or shared experiences.