Probably one of the best playthroughs of Arcanum i've seen. It isn't specifically a walkthrough, but it's a very interesting read.
http://lparchive.org/LetsPlay/Arcanum/

I been wondering, where are the "let's play" threads in this forum? Or are they not allowed?
Aaaannnd there's an hilarious Lets play of Fallout 2 in there too, with a stupid character.

NxCmp Started a Lets Play when Arcanum was first releaased on GOG
http://www.gog.com/en/forum/arcanum_of_steamworks_and_magick_obscura/arcanum_lets_play_youtube

A thread detailing playing a game. Doesn't have to be a playthrough. Usually with screenshots, which GOG has very poor support for hence no let's play - threads around.

These days it also means playthru videos usually posted at youtube. In strategy games they are usually called AAR's (After Action Reports). Content varies greatly from just (semi)detailed run thru of events to full blown stories bordering fan novels. The narrator roleplaying their character is also popular these days meaning that if narrator roleplays a thief he'll limit himself to what thief and so fort.

Wow, I'll look some of them up, when I get home.
That sounds pretty awesome !

My personal favorite is the Let's Play of KOTOR 2 located here. Two words: Jedi Jesus.