Have you seen Twelve Kingdoms/Juuni Kokki? Excellent eastern fantasy with a fascinating world, and a deconstruction of the interdimensional schoolgirl genre. One of the best anime I have ever watched, perhaps even the best.
Or maybe Gunslinger Girl? Beautiful and psychologically brutal, wrenches you emotionally like an old rag. Would be my first pick to compete for my all-time Top1 spot with Juuni Kokki.