You want food storage containers to be a few things: durable, dishwasher-safe, microwave-friendly and reasonably good-looking. Airtight and stackable help too. Snapware's Glasslock products are all those things. They've pushed plastic containers out of my house, and hopefully for good.
As you might expect, Snapware's goods aren't cheap. A four-piece locking set runs $US14.99, and an 18-piece about $US48 ($US43 on Amazon when we just checked). The Cool Tools blog, which reminded us of our beloved Snapware, notes that Snapware and nearly identical brands can be found at discounts online and at stores like Costco, but I'd recommend the real McCoy.
Why? Food lasts longer in these containers, and the containers themselves last. Plastic Tupper/Rubber/Zip/whatever containers acquire scratches and perma-stains over time, and one wrong move in the microwave or with a fork leaves them warped or pierced. Glasslock containers take a real beating, and I know this because my wife drops the lunch bag she brings home from work like it's her job, and I often get overeager with scouring pads in my dish duties.
But the real reason Glasslock works as the best leftover and ingredient storage? They're made of glass. When you open your fridge, you see your food inside them, and hopefully think to use that food up. Otherwise, you can also see when stuff is about to turn, and toss it before you're growing intelligent life on the lower shelves.
Snapware Glasslock Glass Storage Containers with Lids 18pc Set Nesting Design [Amazon via Cool Tools]