Enjoyable characters, interesting locals, and a smooth and slick interface make DA:O a fun romp despite a few setbacks.
The classes themselves, this is more of a personal gripe but I would have preferred a few more class choices. Or at the very least, expand the specialization choices to more than 4 strung out skills. Again, a very minor personal gripe.
This might only be me...but I find the inclusion of the "gift" items(sans the personal character plot item gifts) to be a counter-productive choice for a RPG. Sure it seems like a decent enough idea, until you realize it takes away one of the greatest things of the game...the character interaction. If you manage to piss off a character in your party, never fear, for you can just bombard them with gifts until their approval rating is high enough that it seems like it never happened.
Granted its not that big of a deal, since you can merely choose to NOT use gifts, its just a design flaw in my opinion.
The combat system, its not the best...its one of the weaker parts of DA:O, its not a BAD combat system really, but it could have been better...especially considering combat is the second largest emphasis of the game next to character and story plot. During the latter part of the game, say the last 5 to 6 hours, the combat will be quite tedious and you will pretty much be playing through to see the story fleshed out. And to see what happens to the characters you've been leading around for the last 20 to 30 hours.
Also, in the non-patched version of the game at least, the difficulty is incredibly off-kilter, even on normal difficulty very early on you will run into fights that will wipe you so fast you'l wonder when the bandits had time to hire superman to come kick your ass. Its advisable to save often if your playing on a difficulty above easy.
Honestly, those are the only gripes I can come up with off the top of my head, so on to the good.
Now I know everybody has been sort of...lukewarm over the graphics in this game, I really cannot see why...for the style of game that it is(that being a squad based story/character driven linear RPG) the graphics are some of the best I have seen. I mean...when was the last RPG of this type, Mass Effect...?
Neverwinter Nights 2? Anyway I think the graphics are on par with the type of game that it is.
The character interaction and story are great, the story itself isn't very original of course, but the way that its told is entertaining at least. Its a RPG where I legitimately cared about party members and even non-party NPCS.
For a linear RPG it has quite a bit of replay value due to the 6 possible starting origins(which actually DO influence some interactions later on in the game), as well as the different endings for you and also your companions, who have different endings depending on your approval with them once you finish the game.
On a closing note, I love the fact that the main character isn't the "Nameless Hero" with the whole "Wait...why should I be caring about the fact that any of this is even happening?" attitude.
Regardless, for anybody that loves older style linear RPGS (Baldurs Gate/Icewind Dale/ME/NWN) this game will definitely keep them entertained for a good long time.