(This post can be summarized as "system matters.")
What is your game about?
Think about games you play, and compare that answer to what the game is supposed to be about according to the back of the book, the hype, the introduction, and the GM's section. Now compare that to what the rules actually support.
Warhammer Fantasy Roleplay is alledgedly about investigation, mystery, and grim fantasy. Does it have rules for investigating Chaos Cults or corrupt watchmen? No, but it has rules (very gritty rules) for fighting them. So Warhammer Fantasy Roleplay seems to *actually* be about fights that end up with savage dismemberments, or running away from fights. However, most of the adventures I've seen over at blackindustries.com are based around putting the PCs in a situation with several NPCs with conflicting motivations and sorting it out.
Compare this to Dogs in the Vinyard. Does that last sentence sound like what Dogs is about? Yes, because that's what the game-setting support, and its also what the rules are designed to do.
The traditional roleplaying games fall into the trap of combat. This is a pitfall of certain design ideologies (Sim-realism among them) that dictate that combat must be the most detailed ruleset in the game, or even the only detailed ruleset in the game. Compare Dungeons and Dragons (any edition of your choice) and a World of Darkness game (any line or edition of your choice.) Think about what sort of play the game is "supposed" to support. Then look at what portion of the rules in each book is devoted to killing people (and/or taking their stuff).
You'll find that WoD tends to have less rules per book, and cramms in alot of setting information. But for both games, the majority of the rules are combat related, and the non-combat rules leave much to be decided by the gamemaster, making noncombat actions often being GM-fiat.
Now, if you're looking for a game about high fantasy politics, is D&D the best choice? If you want to play a game about how Vampires relate to other Vampires, is the World of Darkness really the best choice?