Folks said before that your quest was unclear. Your clarification makes it even more unclear! Folks asked why you want to know, and you answered "Well, I'm thinking of maybe make various graphs". That's not an answer to the question.
Good point, I guess. I think this is one of those things where it's impossible to even ask one question and expect any conclusive answer, because that answer will only reveal a piece of the puzzle. But for now, I just want to know what titles of games have sold for which platforms. In some cases, I know that's impossible to know. I'm just trying to figure out what makes it impossible to know these things, as well as get whatever information that is possible to know about.
As for why I want to know these things, it's mostly something that I think could help me design better games. Knowing which games have released, won't itself help me much. But whatever I can subsequently produce out of that information, could potentially be helpful. Like comparing two games of the same genre and setting, one that succeeded and the other bombing terribly - and why those things happened.
Is this a Ph.D. project? Are you hoping to publish this study? Are you hoping to sell it (the way statistics and market research are sold)?
I'm asking according to a line of thought, really. I might publish it as various hypotheses at best, and I've never considered making money on this. I'm likely just gonna make it publicly available on my upcoming website. As of now, I've been just writing down a game list that I thought I'd extend upon as far as possible. Mostly games that I've played myself (roughly estimated to around 600 total), but then I got this Gumpish idea of "I'm already doing this, so might as well do that...". So, I'm gonna see where that takes me.
I also appreciate that you point out the issue with clarity. I'll think about that, because I don't want to ask redundant questions. But I feel like I've gotten some good answers already, and google, wikipedia and yahoo are definitely my friends here.
(I'm also looking into how to get better at datamining.)
Edit: Fixed the OP somewhat.