Haven't been there lately, but I used to enjoy the paczki at Star Bakery on Nassau Ave across from the Busy Bee. (It's not plum season yet but I love their plum cake too.)
I also tried the paczki at Syrena Bakery up on Norman a few years ago - not impressed, although I like their sunflower seed bread a lot.
207 Norman Ave, Brooklyn, NY 11222
43-21 Kissena Blvd, Queens, NY 11355