Stein Field, 3 percent (2/64): Jefferson Avenue and Murray Street.
Maybe it’s just me, but this seems to have a striking resemblance to Tully Field.

Berzenic Park, 6 percent (4/64): St. Georges and Central avenues. Built on the former site of the public library, which was flooded during 1999’s Tropical Storm Floyd, Berzenic has tennis courts and a playground.
Madison Avenue/Greenfield Park, 6 percent (4/64): Madison and Westfield avenues.
Another county park that was refurbished a few years ago when a fieldhouse was added. You’ll routinely see the soccer fields being used, and it also sports playground equipment.
Bezega Park, 1 percent (1/64): Allen and Union streets.
One of the many sections of the county’s Rahway River Park, it’s a little more secluded than most. In fact, one reader emailed his vote for this small park near Rahway Animal Hospital claiming to have seen an eight-point buck there.
Brennan Field, 1 percent (1/64): Regina Avenue and Ferndale Place.
Off New Brunswick Avenue, this one has a ballfield and basketball court.
Flanagan Field, 1 percent (1/64): Wall Street and East Milton Avenue.
Not unlike the other small neighborhood parks, it has a playground and ballfield, sandwiched between homes and an industrial area near Linden.
Hart Street Park, 1 percent (1/64): Hart Street.
You wouldn’t think much of a park that’s sandwiched between a go-go bar, a sewage treatment plant and water tower, but it hosts quite a few community picnics and the like.
Howard Field, 1 percent (1/64): Stockton Street.
Not much too it, but another good-looking neighborhood park with playground equipment, ballfield and picnic tables.
Riverfront Park, 1 percent (1/64): Lawrence Street near East Hazelwood Avenue.
Access via Lawrence Street doesn’t look like much when you park in the lot, but follow the boardwalk along the river and you’ll see some views of the incinerator that you’ve never seen, and of the Rahway River too, of course.
Ross Park, 1 percent (1/64): Essex and Johnson streets.
The newest addition to the city’s park system, it opened in May and adds to the greenway along the Rahway River. It appears to have been built with the nearby Golden Age Towers in mind as the exercise stations seem geared toward seniors.
Skarrow Field, 1 percent (1/64): Montgomery and Washington streets.
This was one that I didn’t know about. There’s a playground and field behind Cleveland School, which fronts East Milton Avenue.

Several parks in our poll received zero votes:
Kiwanis Park: St. Georges and Central avenues. Across St. Georges from Berzenic Park, it’s a little swath along the Rahway River.
Madden Field: Capobianco Plaza. The ballfields are home to many of the youth athletic leagues.
Wheatena Park: West Grand and Elizabeth avenues. In the rare instance when I feel like running, I like to take a route through Wheatena and follow the sections of Rahway River Park up the river along River Road and back.

Thanks to reader Matt for finding this map of Union County parks (.pdf), where you can see some of the ones listed above. I came up with this Google Map with placemarks for each park. Also, a big thanks to Mr. Rahway for help in compiling the list of parks.