I use the AP test tube kits. My only gripe is the test tubes themselves. They couldn't possibly design a container that is more difficult to put water in or pour water out of in an accurate fashion. Also, the #$%& things have such a small bottom, all you have to do is look at them wrong and they fall over. Given that my fingers are always wet and I'm always dealing with at least 6 to 8 test tubes at a time, I'm bound to knock one over if not drop one on the floor where it, of course, shatters.
The old test kits had plastic tubes with nice little stands so they weren't so easy to knock over and break. Some marketing genius must have realized that people would have to buy another test kit if they broke all the tubes. Myself, I'm looking for an alternative at a scientific supply store.