For some reason only games I have ran adventures are fantasy games. Fantasy games I mean games like Praedor (Finnish low-fantasy rpg based on graphic novels), Dungeons & Dragons 3rd edition, Blue Rose, Lamentations of the Flame Princess and Fading Suns (even though Fading Suns is science fiction I see it more fantasy than sci-fi). Other games I have ran are more character, location or politics of the place oriented. I haven't hand adventuring in Vampire: the Masquerade or Call of Cthulhu for example.
In my Vampire games focus is in city and how character fits in or what character does in there. It is not like adventuring but more like life in there. Also Call of Cthulhu games have been revolving around how character is affected by the situation rather than character following a path of an adventure.
In fantasy rpgs (like those I mentioned in the beginning) it's been somehow easier and more natural to run an adventure. There's a beginning and a end and things in between and character follows it. It doesn't matter that much what kind of character is as similar adventure would have been with different characters. Of course some parts of the adventure might differ depending on character's actions and even the outcome of adventure might vary based on that. But for fantasy type of games I usually make an adventure. Something where it begins and what should have accomplished in a way or another for adventure to end. Other games are more freeform for me. There is this overall situation where character is put and while playing we see what happens to the character.
Difference is, that in fantasy games character is put in the adventure and we see how character deals with it and what he does before it ends and how his actions affect the ending.
In other games there is a situation, starting point, we put character there and see how character affects the surroundings and how surroundings affect the character.