Original Sin is nothing like Skyrim at all. It's also, as far as I am concerned so far, a lot better than Baldurs Gate, NWN, or any of the older (legendary/legacy?) isometric view RPGs. To be fair, I think a lot of my problem with those games is that I wasn't gaming back then and when I started gaming, around 2007, the graphics were just too dated for me and I couldn't really get into those older games.
I don't understand all of the hate for Skyrim, it's a great game. I played it for about 130 hours and I don't recall any really annoying game killing bugs. It had probably been out for about a year before I started playing, so maybe all of the big bugs were patched out before then.
For a first/third person action RPG game, Skyrim is the best ever as far as the smoothness of the game engine is concerned. In other aspects, it's not as good as Two Worlds 1 or 2, Fallout NV, Divinity Ego Draconis, or any of the Gothic/Risen series(besides Risen 2, it's better than that), but it doesn't suck either.
Also, as much as I like Original Sin so far ( I can't stop playing it), the camera is a little annoying at times. I guess that's not a bug, but I would say that it's flawed and needs improvement. But it's the best game I've played in a long time. There's so much to do and that you can do, it's a little overwhelming.