Tough question, I'm a big AC fan, and I liked them all. The first one.. not so much, it was a bit annoying running back and forth all the time, I enjoyed AC II the best as far as the game and story goes. However Brotherhood included the training assasins part which was a plus, and revelations took that even further which was great. The downside to Revelations is the fact that the tower defense can get annoying, and the Desmond part sucks (IMO)
Why not just do the 2 game deal and split the cost? Of course it both of you did it you could have 4 games at a time that way, but I would think the novelty would wear off after a while. Seems much more economical to do it with one membership, (which I believe you can have more than two games out after you have been a member for a while) Also with the unlimited PC play, it seems there is enough to keep everyone happy for a while.
First and foremost, make sure your pop-up blocker isn't enabled. Chances are it's trying to prompt you for the download and it's being blocked.
I had a similar problem the other day, when trying to download one of the unlimited games, I had to get the download client and download it that way rather than just downloading it directly.
If none of this helps, I'd recommend getting in touch with gamefly support. (top right)
It's pretty self explanatory, low availability means they dont have many, whereas funnily enough, high availability means they do!
Now, so you suppose your chances of recieving a game they don't have many of is equal to your chances of getting a game they have an abundace of?
You know, come to think of it, I bet that's why they tell you to keep 10 games in your queue.