Kikoskia. English Let's Player. Mostly focuses on RPGs and FPS games with occasional forays into other genres. First one I watched was his Ultima VII playthrough which including the expansion was a huge over 300 video affair. Conversation, focused on gameplay commentary.
Minimal/No swearing.
Necroscope86: English Let's Player. A wide range of game types but with a bit of a focus on horror. Also does videos of team play with friends. First series I watched was a playthrough of X-Com: Enemy Unknown involving one Vladimir Romanov. I'm not sure if that series is still there as he deleted his account about 2 years ago, back up and running now though. Conversation, focused on gameplay commentary.
Minimal/No swearing.
TheRPGMinx: English Let's Player. Previously MangaMinx (old account still up with videos). Heavy focus on horror/survival games, along with Co-op with other LPers such as Necroscope86. Can't remember the first series I watched but I have noticed she tends to swear a lot more now then she used to.
Near constant swearing.
Meowing Kittens: American Let's Player. More commonly known as Takarifreak. Focus on Pokémon, LEGO video games, and old Sierra Adventure games. First videos I watched were King's Quest play throughs with Luchajin. Conversational commentary, veers off gameplay occasionally.
Moderate Swearing (I think, can't exactly remember).
Lucahjin: American Let's Player. Focus on Sierra Adventure games, adventure games, Paper Mario series and some older videos of Barbie video games. Humour is quite bawdy, also does a lot of silly voices for characters. First videos I watched was King's Quest series with Takarifreak. Conversational commentary, veers off gameplay occasionally.
Moderate Swearing (I think, can't exactly remember).
Scott Manley: Scottish/American Let's Player. Heavy focus on Sci Fi video games, most commonly Kerbal Space Program. Has knowledge in the field of astronomy so videos are often quite educational as well as entertaining. Does occasional videos of other sci fi themed games. Educational commentary focused on gameplay.
Minimal/No swearing.
Reformist: English Let's Player. Heavy focus on Mount and Blade. Tends to do a few videos of a suggested mod, then if videos are found entertaining will move it to a full series. Also playing through X-COM: Enemy Unknown by Firaxis. Commentary very focused on gameplay, even handed.
Minimal/No Swearing.
Robbaz: Swedish Let's Player. No real focus. Releases 10 minute videos every 2 days or so of gameplay. Videos are edited to show most interesting parts. Several videos may focus on one game but most/all retain 10 minute timing. Humour can be crude with commentary remarking on silly goings on in videos.
Moderate Swearing.
Hercrabbiness: I think American Let's Player. Rarely updates now but a number of series are available to watch on channel. First series I watched was "Laura Bow: The Colonel's Bequest" adventure game by Sierra. Also done series on Ben Jordan adventure games. Conversational but focused on game commentary.
Minimal Swearing.
Yahtzee19: English/Australian Let's Player. Most well known for Zero Punctuation. Also does weekly hourish long videos with friend where they talk over gameplay about current games industry topics. Account also has several Let's Plays of old bizarre games. Commentary focused on news and current games industry topics.
Moderate/Near Constant Swearing.
Byron4545: German Let's Player (I think). Heavy focus on older RPG's. Done series on SSI Gold Box DnD RPGs as well as Ultima Underworld, Ultima 4 and various others. Videos tend towards 30 minutes long and commentary is minimal but always focused on gameplay.
Minimal Swearing.
Cauchemar89: Swiss Let's Player. Focus on Gothic series with various others like Yoshi's Island interspersed between. First Let's Play I watched was Gothic 1.
Moderate Swearing. (I think, can't exactly remember).
Aavak: Welsh Let's Player. Heavy focus on simulation games. Actually a member on this here Bay12games forum. First let's play I watched was Cataclysm series. Does a good job of explaining mechanics while playing, focused commentary.
Minimal/No Swearing.
Tad30s: Not sure of nationality Let's Player. Heavy focus on Total War series, more recently horror, survival and stealth games. Commentary tends to focus on gameplay, with calling of commonly used tropes and statements of opinion. Also a member of Bay12games forums.
Frequent Swearing
666theheartless666: British Let's Player. Heavy focus on horror games. Play style tends to be blind with much bumbling around, scared reactions to monsters. Let's Plays of SCP Containment Breach, SCP Stairs, Amnesia, Slenderman etc. Commentary casual, conversational with sudden changes in volume when surprised.
Minimal Swearing.