It all depends on the game availability and how many copies of the game they have, so even if its your #1 if its not available, they will ship out the next one on your list that is. Availability changes everyday with games being received back and games being sent out. In the Help section your Game Q is outlined as followed:
At the main menu select Options, then select Extras, then select Enter Code and enter the following code:
This unlocks golden sledgehammer for single player use. Now in order for you to actually use it, you have to either buy a "Sledgehammer" from the upgrade store for 25 salvage or start a new game to get it.
Its a retail disc with 4 XBLA arcade games on it, each game having its own set of achievements and each game being worth 200GS. Unfortunately, listing them all requires more space than given for answering a question. But you can find them all here:
Not unless the new format plays on my current 360. If they are finally upgrading to Blu-Ray discs or something else and it requires me to buy another 360, then i'll pass. I will wait until the release a next gen console for that.
Its normally 3-4 days after a game is listed as "received" when you send it back. Or in your cause, since you purchased it, they will probably send you out the next available game in your Q within 3-4 days of your purchase.
Put in in your mailbox, your postman will pick it up when delivering the days mail. Or drop it off in a US Postal Service mailbox (normally large blue mail boxes), or take it directly to a US Post Office.