Everything depreciates in value eventually, but a few things have short periods of appreciation, and then depreciation. Games that are hard to find: Marvel Vs. Capcom 2, Chrono Trigger, Metal Slug AES, Suikoden, etc. Collectible trading cards and beanie babies will usually go up in value when supply gets really low and demand is still high, but those types of items take a huge hit much more quickly than other items will. Some classic cars, certain types of antiques, original works of art. A fairly decent list can be made.