Okay, I don't understand these forums or how to navigate to the correct one so I will put this here.
I would like to think that I could go into my games history, or games list through my achievement score, and then select a game to view any DLC offered, buy it, and then play it.
Sadly, that thinking would be wrong. If you click my gamerscore and then follow the link to Bioshock 2 (PC) you will get to an error page. I don't understand how that sort of thing gets overlooked.
Obviously GFWL and XBL are different beasts, but they do use the same sign ins and could benefit by better integration with each other. The website is slick, but not so slick when I get a broken link right in my game history.
I might make a similar post in the GFWL forums, but it doesn't look like anyone who works for Microsoft checks it anyway (see this post about a broken link that is still broken) http://forums.xbox.com/gfw/general/forums_feedback/f/283/t/18806.aspx