Pincecone is reputable. They pay $5 per survey. I've done one before... for salad dressing. They paid about a week after I got the survey.
However, your eligibility with Pinecone depends on your lifestyle, age range, and what not. The salad dressing one was the only one I was qualified for.
Otherwise, it is safe to be suspect of anything else that's out there. Get rich quick schemes that fool you into thinking you will get rich quick are as prolific as weeds out there.