You should choose an executor that is:
Trustworthy
Detail-oriented
Living reasonably close to you
Somewhat knowledgeable of their responsibilities and duties
Likely to survive you
You can choose a family member or close friend. Alternatively, you can hire an estate professional in the case of a complex estate.
It is a good idea to name a back-up executor in the case that your first choice is unable to accept the role. People named as an executor have a right to decline the role. Be sure to have a discussion with family members to advise them of your choice of executor so that there are no surprises.