As is custom these days, Rockstar's LA Noire will be offering a variety of pre-order incentives at different retailers. It seems that GameStop is the only place worth buying from, however, since it comes with a full downloadable story -- The Naked City.
Rockstar has released a trailer for this unique mission, in which players must investigate the alleged suicide of a fashion model. Looks pretty groovy, and slightly more interesting than the downloadable costumes being offered elsewhere.
Consider me sold.