I am playing now my second playthrough, and the main quest still have many bugs.
They had almost one year to fix the bugs, but instead, they preffered to make a DLC.
I am not buying dawnguard until my game is fixed.

Then you'll never buy Dawnguard unfortunately.

Morrowind still has bugs... That's ten years old. Bugs are something every developer has to deal with (you really won't ever get them all), and at least on PC there's mods for it. Bethesda can be especially bad in this regard, but all in all, I -and obviously many like me- feel bethesda more than makes up for it in their games, and the longevity of them.

I understand if there is bugs in side quest, but we are talking here about the main quest!! Its hard to miss a bug in the main quest. And there is a lot of them, especialy when esbern comes to aid us.
I find myself exiting and entering the quest room every time there is a "cutscene" with esbern.

I think we can pretty much consider the base game to be "done" as of v1.6.