The Seastreak Ferry from midtown or lower Manhattan is a real pleasure. There is a snack bar on board, and you can enjoy beer, wine or a mixed drink while you cruise. You get to Sandy Hook in about 45 minutes. However, the cost may seem a bit pricey to some: it's $45 (cash only) per person for a round-trip ticket.

If driving is the only realistic option for you, I'd avoid weekends and go during the week. Our experience is that on summer weekends, you can expect crowds of 2,000-2,500 at Gunnison, which means the parking lot fills up fast and you wind up walking a mile or so. And this is after a 1-1/2 hour drive from NYC.

On summer weekdays the crowds are smaller---in our experience, there are "only" about 500-600 people at Gunnison, which is large enough to get lost in the crowd, but small enough so that you'll have no trouble getting a parking place. Parking is "free," but it costs $15 per car to enter the National seashore area ($7.50 if you're 62+ and have a senior pass).