First thing is first, I must admit that Skyrim has and does offer a lot more voice differentiation comparitvely speaking over any of it's predecessors, but I have a different gripe.

Bethesda had announced they had a number close to 70 voice actors for skyrim (or close too) which is a significantly larger number compared to oblivion for example, however
In my opinion I feel the voice acting itself is rather bland. You can definetly tell that the actor is merely reading from a script, and theres no feeling in what they are saying, which not only fails to draw me into the conversation but the dialogue just doesnt seem interesting enough to keep my attention. On top of this I feel as if they have stereotyped certain voices for certain types of people, such as most jarls have a very similiar if not the same voice, as well as most male shopkeepers.. and even certain key characters! jeez you would think that bethesda would have the common sense to AT LEAST distinguish the important NPCs from one another..

however I cannot say that EVERY conversation has been boring because there are a small few that I've had the pleasure to fully enjoy, most notabley (off the top of my head) is cicero.

I do not wish to give away any spoilers, but when conversing with Cicero you can't help but thing "damn this guy is effing crazy.." ...and I love it! the acting is superb, you can ACTUALLY see this npc's personality, you FEEL his anguish, unlike the other 95% of the npcs who all seem the same, no personality, bland and not unique at all.

Now ive completed most major quests and factions, keep in mind. but I'm wondering if anyone else can think of any other awesome characters such as cicero???

Cool story, bro. I guess it's just not your cuppa tea.