I have not tried Dark Souls so not in the position to comment on it.
Elder Scrolls RPG games are good but I find BioWare RPG games more addictive and fun in comparison on average.
Dragon Age Origins is an excellent RPG game; Ultimate Edition, in particular, covers all Origins affiliated expansions in a cohesive manner. Highly recommended.
Dragon Age 2 is pathetic to be honest. I don't know what BioWare had been thinking while developing this nonsense.
Haven't tried Dragon Age 3 yet but it is getting good reviews on average.