Have you heard the news? The most complete version of the long-lost unfinished Sega Saturn game Sonic X-Treme has surfaced and been sold for $2,500 to a private collector. However, the game isn't so much an actual game, but a single level proof of concept demo to show Sega's Japanese executives. There's a lot of lore with this story (as you may know), but what I want to point out today is how Joystiq is handling the news. While announcing the sale the blog asks which unfinished games are worth $2,500. The Joystiq readership has responded overwhelmingly with Halo 3 and The Legend of Zelda: Twilight Princess.
I think the Joystiqers are missing the point. Both of those games are still in development and will be released at some point soon. The idea here is to choose an unfinished forgotten game from years gone by that would be worth the large investment. Correct answers to this question include Star Fox 2, Super Mario FX, Resident Evil 1.5, the original Mother 3, and Virtual Boy Mario Land (among plenty of others). Exact dollar values vary, but paying large amounts for a game that will be in everyone's home this time next year is not a wise investment.