To be honest, on my first try I went with easy, in order to get used with the game, but after a while of playing it, I'm proud to say that I go with nightmare difficulty all the way!
What are the difficulty differences between Hard and Nightmare? I know the biggest difference between Normal and Hard is that AoE spells affect everyone not just enemies...
Normal is good enough. I don't like to spend hours on encounters I could have won with only a small amount of challenge. My backlog is way too big to waste my time with such pointless challenges. I do try to refrain from reducing the difficulty, however. That's only a measure of last resort in case I get stuck.
I always just play casual/normal. For me, storyline has always taken precedence over gameplay, especially when the fight scenes are just button mashing. Working your way through dungeons can only entertain you for so long before you just want to skip the bloody fade... but luckily, there's mods for that.
It's funny, I've been playing Dragon Age: Origins for years on the casual setting...I just recently stepped it up to normal.
I play normal difficulty. I always play normal, not only this game but most of the games I've played.
I usually went with the default difficulty at first. After my first finish of the game I played through on a harder difficulty next. If I really liked the game I'd just keep increasing the difficulty. However, a few games tend to increase frustration and tediousness and sacrifice enjoyment... This game wasn't one I'm happy to announce.
I replayed the game on hard and I must say, it was a better experience then playing on normal. I think certain games are more fun if you play them on harder difficulty.