while you're out there you can hcekc out round valley and spruce run reservoirs - lots of great runnign out in the hunterdon county area too.
basically there are good places scattered all around northern nj (don't know much about south jersey running) - basically stay out of hoboken and you'll be ok.
surprising that nobody has mentioned allaire yet. great ocean county park where you can get a great long run in. just watch for ticks in the summertime.