Trader Joe's is fun to visit occasionally, but not for regular grocery shopping.
Things I like about Trader Joe's include:
-bright and fun atmosphere
-they have little shopping carts for kids
-good prices on oils (especially coconut and olive)
-2 Buck Chuck
-Nice (and affordable) selection of cheeses
-Lemon turnovers
Despite this, I think Trader Joe's is very overrated because:
-Poor selection of "basics"; what I mean is that if I have a recipe in hand and go to Trader Joe's, it is likely that I will not be able to find every ingredient
-too much pre-packaged and heavily processed foods
-it's small and hard to navigate when crowded
-produce is sometimes of questionable quality
-I don't love their cereals
All-in-all, Trader Joe's is ok, but there are better places to go.