I hate plastic ice cube trays. They're way too flimsy and breakable when twisting out the ice cubes making them useless for freezing things like homemade baby food, leftover herbs, and coffee.
I fondly remember metal ice cube trays and their elegant method of dislodging the cubes.
I haven't looked in the thrift stores yet but metal ice cube trays might be found there. They are definitely on eBay.
If not, new aluminum ice cube trays are available from The Vermont Country Store or Miles Kimball. Looks like they both use the same Chinese factory as the source.