I went with a sorcerer, and my spells got to do so much damage I tore through almost every boss in the game in no time. The best ones are the homing spheres, since you can cast them far away then block on the way in while they go do damage. I went pretty much all Int and Dex with a little End, had a upgraded magic spear for almost the entire first playthrough. The only change I made was while I was fighting the Magic resistant enemies in Seeth's area I used Queelag's fury and kept my Humanity at least 10. I never tried the weapon and shield spells since I figured they were just less effective versions of melee builds.