Depends. Medal of Honor could get you more play time than Fallout New Vegas ever could. Because FNV is going to be a single player game, probably mostly like Fallout 3, worth only one long drawn out playthrough with anything other than that being bored. Same with Fable 3, although I expect the gameplay in Fable 3 to be more fun than FNV. Medal of Honor probably has a 6-10 hour single player, but if Dice do it right (like with BFBC2) the multiplayer in MoH could give you numerous amounts of hours.
Can't say much for the other games as I don't plan on playing them. In fact what I plan on buying is Two Worlds 2 and Fable 3. Might get MoH and FNV if I find they're worth the $7 I spend to rent them. Castlevania and Gothic 4 are also in that area. Truth is, October is gonna be a big month for games as you say, and the best is gonna lie in what you like to do. FPS multiplayer will give you more time than FNV, of course you might like what I find boring, so FNV could give you more time. Between FNV and Fable 3 it would depend on what type of RPG you like, and what setting it's in etc. I'm more akin to Fable 3, but that's just me.
Can't say much for the other games as I don't plan on playing them. In fact what I plan on buying is Two Worlds 2 and Fable 3. Might get MoH and FNV if I find they're worth the $7 I spend to rent them. Castlevania and Gothic 4 are also in that area. Truth is, October is gonna be a big month for games as you say, and the best is gonna lie in what you like to do. FPS multiplayer will give you more time than FNV, of course you might like what I find boring, so FNV could give you more time. Between FNV and Fable 3 it would depend on what type of RPG you like, and what setting it's in etc. I'm more akin to Fable 3, but that's just me.
Two Worlds II was delayed to January 2011 outside of Europe.... though I guess if you're in Europe you don't have to worry about that.