When you compare investment across years, wine seems to be a good choice. Dig deep into buying high class french wines, like Bordeux. In ex. Pauillac or Margaux, some of them gain around 8-10% per year depending on the year of harvesting.

There are many online sites with wine prices. A good way to start is to hunt for bargain offers for high class wines in regular shops. They can;t let themselves keep it long as the inventory turnover hast to be high there. But you can keep it and if you will, you might get a hefty 150% investment over a period of few years.

Cheers.