pure dex builds are common, good ones aren't IMO. Int + whatever is a different story.
magic is over powered against PvE but it's generally bad in PvP unless you're in a party or you have dark magic to spam. anyone who isn't dumb can dodge spells easily (or pyro). I tend to take people out with the moonlight greatsword because i love melee and that weapon is godly.
I also go with the heavy weapons. right now i'm love with the 50 str required dragon weapons.
Speaking about magic, I'm just wondering, is there any way to beat a faith based character that spams force when you're playing pure melee? I don't often play PVP but everytime I do and I encounter a guy spamming force I get completely wrecked. It hits super fast, does a lot of damage and destroys your endurance bar if you block it...