You can try Metropolitan Plant Exchange on Northfield Ave in W. Orange.

Also, the Home Depot on Springfield takes pretty good care of their plants and their staff is even somewhat knowledgeable about how to care.

Occasionally I have had luck in some of the supermarkets, like the Shopright on Morris Ave or the Shopright on 22 in Hillside or the Shopright in Essex Green Mall in W. Orange, but I wouldn't make a special trip there.

I have often found various Lowes to have some nice houseplants but the one on 22 in Hillside/Union doesn't have anything too interesting by way of houseplants.

Tuck away in the back of your mind Maplewood Garden Club's annual plant sale. It's held every year the three days before Mother's Day - in the Maplewood pool parking lot, off Boyden Ave. They always have some interesting, different houseplants among the offerings and the "sales staff" of garden club members is quite helpful and knowledgeable.

What kind of houseplants interest you? What conditions does your home have? If you have a particular interest in something, I have lots of houseplants and can make you some cuttings! I live in MW too.