Most people I know have a preference for what kind of class they like to play and usually the first character they create in any game will show that preference. For me, I am a beefy melee lover.
My first character in WoW was a warrior. My first character in D3 was a Barbarian. As time goes on, you try out other classes to see what else you like. In WoW, I found out that I really enjoy both tanking and healing. Especially healing on a druid or shaman. In Diablo, I really enjoy sprinting around and whirlwinding shit to death on my Barbarian. Both my Warrior and Barbarian are beefy (I feel like Cartman lol, BEEFCAKE!!!).
My wife prefers ranged DPS. She doesnt like being in middle of all of the mobs if she doesnt have to, especially in instances.
Every person has a much difference preference. What are yours?