New Vegas Iv'e played through quite a few times just to try out all the different ways I can take the story, not to mention even the DLCs have multiple ways you can go with it and potential to role play. I also found the characters to be much, much better in New Vegas, Old World Blues probably has some of my favourite video game characters right now, personality wise.
thats exactly my take on it, characters are also true - without spoiling anything there are some really (potentially) nice characters in skyrim (babette for example or how she is called), but bethesda simply never really uses that potential...
lol i know you cant have everything but
the realism from mount & blade
the difficutly and fight-feeling from dark souls
the factions and choices/consequences from new vegas
the character development and freedom from skyrim
and the character depth from dragon age would make for a pretty aweseom experience...