Palmetto Island State Park

Loved Palmetto Island State Park. It was a couple of years & storms earlier and it was super. Far better than Grand Isle, but of a different ilk, both are nice.
Palmetto has more secluded, private sites where Grand Isle is more big rig oriented.

Never been.

Everyone I know who has stayed there (maybe a dozen) loved it.

However, based on a recent hurricane and a major tropical storm flood rains, I would urge you to call the park and talk to them, or the Abbeville Chamber of Commerce, about current status and any possible issues such as electrical power issues.

Personally, we have planned to visit Grand Isle SP this winter. Even thought it is currently closed due to hurricane damage, I will not plan on a visit for at least a year.

Other LA SP currently closed are Tickfaw SP (we have stayed there - nice), Fontainebleu SP (another we like), Fairview Riverside SP - these three are on the north side of Lake Pontchartrain.

Also closed is Bayou Segnette SP (just across the river from New Orleans in Westwego)

Abbeyville also has a city RV park which is popular with snowbirds.

EDIT - Of course being in southern Louisiana swamp land - be sure to take good mosquito repellant. Even in the middle of winter.