I think it's dumb to try to make a character who does EVREYTHING so far i've had a thief character, and a mages guild character, i went through both of there respective quest lines, im currentley on an Imperial who i think i'll also make my MQ character. Afterwards i plan on making an Assasin then fighters guild etc..

Yes, I do. I have a character that is only for the Companion's guild, due to the fact that I know what happens later... Also, I don't have my main "good guy" moral character doing anything involving the Dark Brotherhood, or Thieves Guild. I also have one specific College of Winterhold character, as I don't believe it suits my others so much.

deffinitly as i find it comical you can be the leader of everything and in some cases those factions have conflicting interests. the exception to this is the dark brotherhood and thieves guild since two of the thieves guild members admit doing work for the dark brotherhood.

Same here it just makes sense from a role-play perspective to have separate characters for each guild (though as previously stated DB and Thieves Guild are pretty close so here's the exception). To me it fits not only your character, but the play style as well.

Coming from Oblivion where all my chars became masters of all the guilds, it was odd at first knowing certain characters I played would be excluded from certain quest lines, but I've found the game to be much more enjoyable, which is what matters.

Just my thoughts, you should play however you want to.

Like others here, I do it for roleplaying reasons. I have always done this in Elder Scrolls games.