Trader Joe's is like that laid-back, Hawaiian-shirt-wearing friend who's always experimenting with something new. He's funny, helpful and always in-the-know. The first local outpost of this California-based chain opened in October 2004, and now Trader Joe's boasts four area locations — in Brentwood (the original), Creve Coeur, Des Peres and Chesterfield. The grocery shelves won't have everything on your shopping list, but TJ's will more than make up for that with its abundance of signature treats such as mini chocolate cupcakes, hummus galore and deliciously inexpensive wines.