There are two main themes in the game: Elven Mythology or Andrastian/Chantry.
Elf Theme:
I'd recommend a female elven rift mage. Males have funny arms and there is a special romance you can only have as a female elf int he game. You will control the battles and push your enemies around with god-like force. It's quite fun and there is a lot of elven themes in the game. Necromancers can dish out some serious damage, but I think they are less appealing because their primary form of control is fear. Mobs running around don't bunch up like you need. Knight Enchanter has a nice niche for elven themes, but it has to be one of the most boring specializations in the game. Rift Mages will spend their time trying to keep weakened on their enemies and finding ways to spend their excess mana. Necromancers will spend their time trying to figure out how to bunch people up for walking bomb hilarity. And Knight Enchanters spend their time desperately charging their Spirit Blade.
Chantry Theme:
If you want to go with the latter, I recommend a Human noble rogue or warrior.
If you go rogue, you will probably enjoy archer more because you'll die less, but you have the option of swapping between ranged and melee. For specializations, I'd recommend tempest. Artificer requires your group to be equipped with some crit gear (and you'd need to know where to farm stuff or acquire stuff) and Assassin is...well, it's boring. Mark of Death has to be the most boring skill in the game...ever. It's overpowered, but boring.
If you go warrior, I think you'll have a lot of fun if you are sure to pick up Charging Bull. It's fun to knock your enemies aside. I recommend a 2H approach. If you are struggling you can always swap to Shield for a bit, but for damage you'll want to go back. There are some good guides out there (http://dragoninquisition.com/) for warriors. For specializations, I'd recommend 2H champion or 2H Templar. Both are a lot of fun. Reaver can do a LOT of damage, but you need gear and special builds IMHO to make it work. You'll die a LOT. Templar can do a wombo combo (Wrath of Heaven followed by Spell Purge) which is really epic on trash mobs. Champion can be a little boring (not very flashy) but you are very hard to kill. Gender doesn't matter very much, but I find male human to be satisfying in this role because you can romance Cassandra. And that is very appealing to a Chantry-loving hero.