They have weekly lotteries, ring a ship bell if someone has a birthday and treat you with food tasting every day. Most of the products come with Trader Joe's labels and therefore can keep the price level low. Only drawback might be that the selections of food is limited.
The lines in the store might be until the front door but that is the whole fun - grabbing groceries on the way and meeting new people :) You can view some of the Trader Joe's Art here: http://www.flickr.com/photos/misterbigidea/sets/72157622389965475/
Su-Sa: 08:00-21:00