Ok, just posted a test video using subtitles (my voice should never be heard by another human being, let alone be used to narrate an LP). I would be very appreciative of feedback on this video, and I may well upload more, although this has sparked my interest enough to want to sign up to Something Awful and post about it there.
http://www.viddler.com/explore/UnknownGnome/videos/1/
Edit: also please ignore the bit about 7-8 minutes as that is a flagrant lie.
Edit 2: Swap Something Awful for youtube, i'll be damned if I am able to register an account.

Think he's been mentioned on GOG before, but I highly recommend Spoony's 'Let's plays'
http://spoonyexperiment.com/category/phantasmagoria/
Phantasmagoria 2
http://spoonyexperiment.com/category/ripper/
Phantasmagoria 2
http://spoonyexperiment.com/category/lets-play/swat-4/
Swat 4

Thanks for that one!
Let me propose one of my own:
[url=]http://www.youtube.com/user/Atomaround[/url]
The guy plays most, if not all, games for the first time, so he doesn't necessarily have a lot of info on the game he's playing and you can forget about him scurrying through, but he's topical and has a good voice.
I enjoyed watching him go through parts of Machinarium.

The same guy who did the Trespasser LP also did a LP of Jurassic Park: Chaos Island, an RTS, and is currently doing an LP of Crimson Skies, although in the case of Trespasser and Crimson Skies, it would be more accurate to call them, as many have already done so, documentaries on the games.

Let's Play Master of Magic
http://www.youtube.com/user/AdvancedBen2E
Let's Play Outcast
http://myronsa.blip.tv/

Quake...............................
http://www.youtube.com/watch?v=aGVvDywNZ30

Dwarf Fortress... Boatmurdered
http://lparchive.org/LetsPlay/Boatmurdered/intro.html

Let's Play Master of Orion
http://www.youtube.com/user/GetDaved#p/u/309/kF94QRsHHtk

I'm surprised no one here mentioned Kikoskia. That guy made total of 1960 Let's Play videos to this date.
http://www.youtube.com/user/Kikoskia#g/p