Mass Effect's Shepards. Mark Meer and Jennifer Hale are great. As well as much of the cast, too!

There are many games that fit the bill (a positive development within the industry since the '90s), but my favourite game in terms of voice acting is probably Final Fantasy XII. Not only was the script fantastic, but the actors nailed the delivery in a way I did not know was possible.

Half-Life 2 series. Never for a moment was I drawn out by inappropriate actions or phrasing of the characters. Valve really picked the cream of the crop for their games, whether it be subtle or ridiculous, they know what they want.

I'll second Nolan North and add Robin Atkin Downes and Yuri Lowenthal to the list. If you hear any of their voices you'll definitely recognize them, they are indeed a bit overused but there's a reason for that, they know how to emote well using only their voice and for that just being a good actor isn't enough, you need to be a good voice actor as well. Which is why celebrity casting is often a problem, just look at Dishonored, a game that had Brad Dourif (of Chucky fame, etc.) underacting.

Ask Licurg. He knows.

He's also the voice as you begin Demon Stone :)

I whole-heartedly agree about Patrick Stewart!

In terms of voice actors who may or may not be well known, I always found some first person shooters to have good voices which helped build a deeper and a more immersive atmosphere, such as Half-Life 2 or either of the Riddick FPS games. And when I first played Crysis I felt like I was playing a movie.

I also don't mind some of the voices in Daedalic adventure games, like the tree sprite in the Night of the Rabbit. I just found that one sort of enchanting (some other voices were annoying though).

Voice acting is one of the best parts of games.

Oh! I can't forget the Assassin Creed games. When I play Assassins Creed, especially 2, around friends or family they mistake the sound alone (without looking at the screen) for some TV show in Italy. When a game can appear to be that cinematic, it's priceless ;)

God yes. It was one of the things that made me put Oblivion down in the end. Morrowind was much less intrusive and jarring overall in the voice acting stakes.

I really liked the voice acting in The Longest Journey, very natural which is rare in computer games.

The Homeworld games have some pretty great VA's, Heidi Ernest (Karan Sjet in the first game, Fleet Intelligence in Cataclysm) and Campbell Lane (Narrator for all three, the Bentusi) being the people that everyone remembers.

Can't really think of a bad voice in any of them really; HW2 might not be quite as good as the others in that aspect, and poorer for a lack of Heidi Ernest (Jennifer Gravness is fine, though I think the Arioch easter egg is symptomatic of some of HW2's problems) but it's still better than most.

I can't seem to find who voiced Fleet Command in Cataclysm right now, but I'm sure everyone who's played it can remember his speech to the Bentusi in the latter part of the game. Very well delivered, that.

Don't know whether I can really recommend Farscape. It was enjoyable enough, but also oh so cheesy in many many parts.

As for Stargate, I definitely recommend Atlantis (my favorite of the three shows) and the canceled-too-soon Universe. SG-1 looks downright amateurish in comparison to them.

Remember Discworld?
Monty Pytons' Eric Idle did some very good voice acting in this jewel of a game ;)

Got to say Mass Effect (Jennifer Hale) and the cast of saints row 4 as you can tell they had a blast playing their parts.

Of the games I have played first choice Oblivion, also enjoyed those of the Gabriel Knight series.

thanks for the input, Im still needing a break from watching these things, watched all 10 series in too short a time, added to that money being tight. False economy though, I bought the DVD's series by series, had I been less impatient and waited a while it would have been at least 25-30% cheaper just to buy the full boxset