To me, writing is like 4th or 5th on the list of what makes crpgs fun.
I loved the Matrix and Speed movies and neither of those had good writing and the voice acting was horrible
Late to this party but I just HAD to comment on the above quote.
I truly believe (well it's MY opinion) that writing is extremely important in an RPG since RPGs, like Adventure games, depend more on story than anything else unlike say Action games where it's all visceral.
Just the same, Action games equate to Action films where you just need some big explosions, great visuals, special effects, gore, etc.
So it makes sense that that the writing in Oblivion, err, Fallout 3 doesn't bother you because it's not a true RPG but an Action/RPG lite.
Of course good story/writing/acting only helps elevate an already good action film or game (God Of War is an excellent example).
But back to CRPGs, the writing doesn't have to be amazing but definitely should be above adequate and some of the dialogue in Fallout 3 is just horrendous (just like in Oblivion). It feels like it was written by and for 13 year olds. It's just too simplified and even unnatural to a point.
Bethesda can definitely learn from Obsidian, just play Kotor 2 or NWN 2: MoTB. Now these weren't the pinnacle of writing in a CRPG, that award would probably go to Planescape: Torment (Vampire The Masquerade: Bloodlines is up there too) but the writing was certainly above average.
But even the writing in Morrowind was much better than their recent games.
Anyway we're all entitled to our opinions so I can understand that you have those 3 or 4 other things that matter most. But to me story and dialogue come first. And if those are mediocre then the RPG better have some interesting game mechanics and entertaining gameplay.