Aren't you a misinformed little fellow. EVERY SINGLE GAME you mentioned is available, in a better version, for the PC. Assassin's Creed's PC version supports DirectX 10 and runs better, and has more types of side-mission. The PC wins.
Bioshock is available on the PC as well. It supports DirectX 10 surfaces, which make the 360 surfaces look like they are made of cream. Plus, it's a shooter. Shooters are always easier to control with a mouse and a keyboard. The PC wins.
Oblivion and Fallout 3: Both games are bug-ridden and have horrible interfaces in their vanilla versions. Not only does the PC version look better in both, but they have 2 of the most active and productive mod communities, with mods fixing the interface to something bigger, like changing the entire game. The PC wins, twice.
Oh! And since you've brough up The Orange Box... well, TOB leads to TF2, which leads to updates, weapons, playmodes, maps and hats... which the console version doesn't have. Ouch. The PC wins by a landslide.
CoD4 looks essentially the same on both versions, but controls better on the PC, being a shooter and all. PC wins, albeit by a really slight margin.
You also mentioned Mass Effect. The PC version's GUI is far superior, the graphics are better and it's easier to control. Plus, you get the bonus mission Bring Down The Sky (I don't know if consoles have it, so correct me)
Let me mention: none of the previous games need super modern hardware to play at 360-level graphics, so that point is moot.
Bioshock is available on the PC as well. It supports DirectX 10 surfaces, which make the 360 surfaces look like they are made of cream. Plus, it's a shooter. Shooters are always easier to control with a mouse and a keyboard. The PC wins.
Oblivion and Fallout 3: Both games are bug-ridden and have horrible interfaces in their vanilla versions. Not only does the PC version look better in both, but they have 2 of the most active and productive mod communities, with mods fixing the interface to something bigger, like changing the entire game. The PC wins, twice.
Oh! And since you've brough up The Orange Box... well, TOB leads to TF2, which leads to updates, weapons, playmodes, maps and hats... which the console version doesn't have. Ouch. The PC wins by a landslide.
CoD4 looks essentially the same on both versions, but controls better on the PC, being a shooter and all. PC wins, albeit by a really slight margin.
You also mentioned Mass Effect. The PC version's GUI is far superior, the graphics are better and it's easier to control. Plus, you get the bonus mission Bring Down The Sky (I don't know if consoles have it, so correct me)
Let me mention: none of the previous games need super modern hardware to play at 360-level graphics, so that point is moot.