I'm on xbox, so vanilla.
I notice loads of tiny bugs, but rarely anything that forces an earlier save re-load.
Oh..and if you wonder just how many bugs are in there.....just go and have a look at the change log in the excellent usleep pc patch....it is thousands and still growing as more are found.
Let me pick a few I've had in my game....
Flying and dropping mammoths...
A flying fox...right across the screen at fifty feet altitude...
Boulder and outcrops you can see under the edge of
A plant or two hovering just above the soil
Slaughterfish swimming just above the water
After a small jump, the landing footfall sound re-repeating for several minutes
Dragonbreath sound not switching off after the fire blast.
The crackling sound of a follower flesh spell still audible minutes later
The first cultists of Miraak have a persistant flesh spell hum well after death
Entire walls of Solitude and Whiterun not loading at all! But if the door is there you can use it!
Game stoppers....
College of Winterhold main doors not opening ( but I got in via the roof door...ha!)
Fighting CoW anomalies in the village...one went inside the steps, therefore unkillable = quest stalled
Blood on the ice...out of twenty plus, play throughs on this....two bugged to a standstill
CoW...stalled by not being directed to Mirabelle after the old boy bites the dust (i.e. Before Labyrinthian)
In Bleakfalls the three pillars to rotate with animal symbols on...can have like three eagles showing as you enter the room, and if you see that the pillars are immovable and you can't open the iron gate.
Once..the three rings on the nordic puzzle door were already aligned upon discovery, and it would not respond!
Sometimes a single cell along a road will repeatedly cause CTD as you enter it.....like five times in a row!
In 12000 hours......the game stopping bugs IN GAME have been very acceptably minor.....thats the good bit
However.....game stability is appalling....I get random screen freezes (CTD equivalent) after anything from ten minutes to two hours.
It is so random you can't predict it....but a few things are very common denominators that seem to trip the game over...
Precipitation...rain or snow
Horse riding
The entire Rift area
Loading screens
So riding around Riften in the rain has a high liklihood of CTD
Some of these could have logical explanations. For example...rain is a lot of little moving parts to keep redrawring...that has got to keep the game busy. Horse riding requires rapid redrawring of surrounding scenery.
It is also not impossible that the game overloads the xbox gpu/cpu.....plus the xbox can get mighty hot in use after an hour or two
Frequently the game stutters or freezes for like half a second then recovers (not low FPS issue...though that happens too in big fights)
The mini freeze is a warning that the game is finding things tough going...better save now, but most freezes are with no warning at all.
Now before some "wise person" says...oh just save often then.......I will tell you xbox 360 only has 9999 save slots and after that you have to reset the xbox and lose all your saves....so if you have been playing like two years and you are approaching maybe save 8000, you begin to realise that at some point...maybe in the middle of a long lived character run......you WILL run out of save slots and your ongoing character has to...well....die
But...I am going to say....despite the fear of random CTDs and the rare game stopping bug, overall the game works well enough to be playable through all quests....even on vanilla xbox
Edit...a little tip for console players to help reduce issues...it should go without saying, but always keep your game disc absolutely pristine. On a music cd, a tiny speck of dirt or minor scratch can be heard as a 'click' in the song playback...no biggie the song continues regardless. But on a data disc like our beloved Skyrim...that speck of dirt is covering up code that the console laser can't read. That means a string of code can not execute correctly..or at all. It will affect something in game for sure. Maybe just one plant texture in one location, or a few missing pixels not drawn....but it could as easily be the code command for load a game asset..a door maybe. Worst case scenario the game boot up code...and Skyrim won't load at all.
The cleaner your disc is the less chance of damaged code.
(Game download over the net is obviously not prone to any of that).