I don't know why I love this game so much...I know we've mentioned this often on our facebook and twitter feed.  But it literally needs to be remade or redone for PS3/360 or for the next generation of games.  Granted, Warhawk is similar - but it does not have the same retcon and nostalgia feel this game portrays.  I'm pretty sure you can find this at most any GameStop for $2.99...

It melds a solid Red Baron style of flight game play with a story telling that is akin to Indiana Jones.  One of the creators was quoted stating that he wanted to "take the idea of 16th century Caribbean piracy and translate into a 1930s American setting." using flight.  The games origins from "Crimson Skies" by  Jordan Weisman and Dave McCoy predates the "DieselPunk" movement (2001) which is somewhat on the same parallel as steampunk.