a superb work of scholarship which no home should be without

If you are anxious for the success of your son in life, for the correctness of his conduct and the soundness of his principles, keep him to Lilly’s grammar. If you can by any means, either fair or foul, induce him to get by heart Lilly’s Latin grammar, you may set your heart at rest with respect to him; I, myself, will be his warrant. I never yet knew a boy that was induced, either by fair means or foul, to learn Lilly’s Latin grammar by heart, who did not turn out a man, provided he lived long enough.

George Borrow's Lavengro (more on Languagehat)

simplicity

Levitation aside, there is a vocabulary test engine called Lavengro that is written in Python (one you can use, in other words, to build your own vocabulary tests); I started learning Python months ago and then something came up, but I'd like to go back to it.