I liked the Sistema stuff we had.

We had Rubbermaid things that tended to leak, fortunately over the last couple of years the dog has found them one by one and I can throw them out.

Lately I've been using the Ziploc pint screw-top bowls. They are just about right for a cup of rice or pasta and some meat and sauce on the top. Gotta be sure to loosen the lid before microwaving.

A couple of things in favor of glass. Spaghetti sauce will stain plastic (and turn all the baby bottles orange in the dishwasher, haha). If you microwave something with fat or cheese on the top it can reach temperatures over the melting point of the plastic and make a ring that you can't scrub off. That's why TV dinners come in paper trays.