Well, if you want to constantly have the smell of decaying intestines in your nose and open, pure, undiluted hatred towards you from the townsfolk, feel free to join the Necromancers. But if, well, you decide that such is not your path, then perhaps the Cartography Guild is the way to go. We not only offer free passes into any civilized nation, but also offer delicious chocolate-chip cookies.
And not only do the Cartographers secretly rule the world, but we make a lots of money through the selling of our maps to those ignorant fools who come to our storefronts. Though you'd start off as a Minor Minion, with enough dedication you could easily rise up the ranks and attain a level with enough power, money, and influence to make changes around the world. I could, if you prove loyal enough, even give you control of some country somewhere (I, personally, have a small island nation of Ge'hee El'smastnat that I use as my own personal vacation home).
Of course, the choice is yours. But do you really want to join the dwarves, and get stuck in a mine all day? Do you really want to join the Necromancers, and suffer the stench of your undead army? Do you really want to join the Weavers, and ruin your figners during the sewing and needlework? Do you really want to join the Divine Synod, and pay homage to some god that won't even acknowledge your existence? Do you really want to join the Occult Brotherhood, and have some demon chew your face off after you make some petty mistake?
If I missed any guild in that, forgive me, and I'll make a note of why they are inferior to the Cartographers.