
These are awesome, have you ever heard of Ript Apparel? I actually got a "Starry Knight" Batman tee that mixes The Dark Knight with Van Gogh's ... well, y;know ... by posting the best picture caption on a Schmoes Know post on Facebook.
You see it in the picture above with me in the middle, Brentalfloss who got the best spot on my tee by being the first guy I went to the sign session for, and his girlfriend. I'll have to snap a pic of the whole shirt, it's hanging in my closet. This was at SGC 2013 in Dallas last summer. I blogged about it then and mentioned it in my "Golden Year in Review" blog last year.
You should definitely check them out too if you like nerdy tees, most of their designs are $10, though I got mine for free.
Of ones you posted, I esp. like Link/Portal, Fallout Cococola, Mega Man(!), It's on Like Donkey Kong(!), and Metroid/ ... can't think of the game, but I love the design(!)
Okami I'd prefer to have a shirt in its wood block style, I don't know what the speed academy is from, and Bisoshock/Powerpuff Girls is a cool combo because of the Little Sisters or whatever, but I haven't played my Bioshock on Steam yet, haven't seen PPG in forever and don't know if I would or wouldn't like it now (was just ok with it as kid), and the design is kinda eh.
For the most part, these are all great though, thanks for sharing!