Reading a prose work, a play, and an epic-length poem or poetry collection in Spanish, Portuguese, Italian, French, and either Latin or German. Some of those by necessity would be re-reads; some of which I've been meaning to do for a while.

For example, I could read Petronius or Cicero, Terence, and maybe Juvenal, Ovid, or Vergil for the Latin, re-read/review something by Gabo or Vargas Llosa, Calderón de la Barca or Vega, and Darío or El Cid for the Spanish, then Camus, Moliere, and Chrétien de Troyes for French, Eco, Buzzati, or Calvino, Benelli, and either Ariosto or Boiardo for the Italian and then Pessoa, Saramago, and Camões for Portuguese.

Hrmm...that might actually be worthy of a challenge, as it would force me to insure that my fluency improves in each of those languages, even if I've read roughly half of the authors named in their native tongues.