I'd second Mary2E ,Analise's and Monitor's suggestion on Avastar. My only choice when parking at EWR, especially after I got rear ended while parked in long term during a snow storm. convienent little bump of snow behind every car when they plowed and then it rained and turned to ice, so the car across from me couldn't get over the bunp unless he gunned it...into my car. ... but that's another story.

If you have the lead time, when I travel with my non freuent flier family, I typically pull up to curb side and drop off my wife and the girls with the bags and golf clubs and then head to Avistar. By the time they have gone to the bathroom, bought a couple of magazines and wandered to the gate, I've dropped off the car and returned to the terminal. Offsite in my experience is the way to go.

Discounts off the website are generally not as good as AAA or sometimes just say Merck Phizer or in the good ol days Lucent.