Let's see... I haven't finished the game yet, but I'm at level 30 in the early stages of Act IV, and I've managed not to get killed in a long while, so I guess I'm doing something right. <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" /> My characters are both fighters. My DK has a big two-handed sword, and skills for that, and goes around slashing things; my hero is an archer, and an excellent one, with skills for that, and goes around shooting things with splitting arrows almost exclusively. (Due to a nice little bug, I think, which I don't mind exploiting, they sometimes take on the characteristics of the arrow in my second slot: poison. Handy, that, shooting poisoned arrows in seven directions at once.)
My hero's stats are all much higher than my DKs, which has got to be because of all the equipment a hero can wear that a DK can't. I don't mind. If the DK's going to be so dang stubborn about his stuff, then let him be his own problem. <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" />
My skillpoints for my two characters are almost entirely sunk into their respective weapon abilities, in one way or another. My hero has bow skills, then convert arrow (splitting arrow), then arrow proficiency (splitting arrow). She also has three or four points of detect traps, because someone always should I think -- you never know when that one will come in useful. My DK's points are mostly in two-handed slashing (and for the moment, while he's building up strength to use a killer sword I've got in the inventory, he's actually using a one-handed sword, and the lack of skills really shows), and then I've also got him a couple levels of identify and a few levels of identify creature. A lot of people prefer to go without those but I'm happier knowing to leave loot or bring it up front, before I head off to a merchant.
I get the feeling my answer was longer than is strictly necessary... <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />