This will be the first xbox 360 DLC I've ever bought, so I need to know what size hard drive to go out and buy for my xbox 360. Mind you- I'm not looking to buy the largest or most expensive because I'll probably only download 2 or 3 things ever in my life. Suggestions? Thanks.

Just get the one you can find for the lowest price. It's not like some DLC is ever going to fill up an entire hard drive.