I've got some of the tupperware mentioned above but couldn't afford more for my getting ready for bubs cook up so bought some called Starmaid from Bunnings (assume you can get them elsewhere too). They've worked really well for freezer to microwave and wash up well in the dishwasher. The lids snap on really well which I liked for liquidy things as opposed to the glad ones. They also stacked really well in the freezer (my tupperware ones are round). I try to be careful with the chinese-type containers as some of them are not great in the microwave - they break down a bit and leach stuff into the food. If you're organised and defrost in the fridge and then reheat on the stove it doesn't matter of course!