We don't travel that often, but when we do fly out of Newark (EWR), we use Vista Parking at Howard Johnson Hotel off of Frontage Road (Exit 14 of NJTP). They charge about $9/day ($8 for AAA members). Efficient service to airport (they've always taken us right away); about 10-15 minute wait upon return (they give you 800 number to call when you arrive). Phone number is 973-465-9400.

I don't know how this compares to alternatives, since this is the only parking we've ever used. They may have discounted rates for longer stays, but our trips are usually less than 1 week, so I've never checked. Depending upon where you live limo service could be cheaper for longer stays (2 weeks)?

Hope this helps.

Nay