True, but they also lived in High Rock (possibly). That's roughly more than half of Tamriel.

I remember the vampires in Morrowind. Now those were scary, at least the first time I encountered one.

Dremoras and Atronaches. These are the most common Daedra. Atronaches are common due to being common summons. Dremoras are common because they are what Mehrunes Dagon prefer to use in his armies and he is the Daedric Prince that normally wants his Daedra in Tamriel, unlike most other Daedric Princes who prefer to keep their minions out of Tamriel unless needed.

Werewolves should be in them all since it was told that Werewolves are in all 10 provinces.

Mudcrabs are also known to be in all 10 provinces and any place with water should equal slaughterfishes.

There is also plenty of Undead.. Actually, some of the creatures that had been in all 5 TES games are undead. (Liches, skeletons, Ghosts, and Vampires)

I'm not really sure TES vampires should count as undead since vampirism acts more like a disease in the series.

They count as undead. Dawnbreaker works on them and "Turn Undead" type of spells worked on them as well. The disease basicly kills you and turns you undead.. Reason why it takes 3 days.. The disease needs time to do its job.