Quickdraw McGraw on 02 June 2008
I'd you want to go the easy route, there are plenty of websites (Wikipedia comes to mind), that can get you up-to-date on the full MG/MGS plotline.
I'd highly suggest renting the games and trying them out yourself, as they're fantastic, but if its just the story you want, that's a cheap way to go.
But it pretty much boils down to whether or not you play through the old MGS' or read through its story. If not, Brawl would be best for now, and you can invest in MGS later down the road.
