GPA. As mentioned above, your GPA is only necessary if you are a recent college graduate and do not have work experience to back you up. There are a few jobs that require a GPA, however, including engineering and finance.
Your goal should be to write your resume with both robots and humans in mind. Many organizations use Applicant Tracking Systems to sort and vet resumes, before hiring managers ever take a look at them. This means that you could have the best experience and qualifications in a whole field of candidates, and a pretty decent resume besides, but your information will fall through the cracks if your resume doesn’t contain the right keywords. Good keywords will refer not only to your experience but to the job description in the posting as well.