Bummer about the Trader Joes, their mushroom truffle oil pizza is restaurant-quality.
Here's an easy dish that I always get rave reviews on. Not really an appetizer but a super easy side or main:
Chicken pesto pasta
Box of pasta (rigatoni or smaller shells preferred over noodles)
Jar of pre-made pesto (Buitoni)
Pre-cooked chicken (either from the deli aisle or a rotisserie chicken you hand shred)
Chunk of fresh parmesan
Cook the pasta and let it cool. Stir in the pesto, chicken, and shred large curls of parmesan over it. Easy and tasty.
For a healthier crowd, i like these salad pockets
Pita bread, halved
Halve the pitas, schmear with hummus, add mesclun greens and avocado slices sprinkled with lemon, salt and pepper to taste. Elegant, filling, and healthy.