Do you think there should be any other major guilds in the game besides the thief, mage, fighters, and Dark Brotherhood? I don't mean little factions, but major guilds. I think It will be interesting to see what you all come up with along with your opinions of my own.

My List
Priest's Guild- heals people (new minigame for healing?) if there were blunt staffs they would probably use those.
Bandit Guild- Yep, you get paid to join together with other bandits (yes, team fighting!) to rob unsuspecting travelers.
Vampire Guild- just a guild for the vampires. not sure what their goal would be though other than to drink a lot of blood. maybe collect blood and sell it?
Smithing Guild- minigame for making weapns anyone?
Merchants Guild- It would be cool to run a store and join together with other mechants. be successful and gain their trust or jealousy. Buy stores and hire help and ruin your competition :celebration:

I personally just want to see more of a mercenary style approach to the fighter's guild, in Oblivion it for the most part seemed like they just did odd jobs. I wish that TES could take on more of a darker side of things when it comes to drugs and other organized crime. But hey, I suppose that's what Fallout is for :fallout:

I'd call it priesthood, and I think I'd prefer them as a society grouping rather than a guild.
Bandit Guild. Sounds kinda corny, but I'm all for Thieves Guild getting some kind of competition. Good thieves vs bad thieves, kinda sorta.
Vampires should be in vampire family clans, not guilds.
Smiths and merchants both belong in the merchants society grouping, not a guild.

With society groupings, I mean speechcraft and dress codes related to groups like commoners, nobility, priesthood, scholars (maybe put priests here), low lifers, merchants, etc. Where some NPC may belong in several groups at the same time. An alchemist could be a scholar merchant i.e, with or without a guild connection. More like Daggerfall in other words. Wouldn't mind 12 guilds, 4 in each of the specialization, but I don't think it'll happen...

I would like a diplomatic, espionage, politics organistation. And maybe trading.

There are such things as merchants guilds so I don't know what you're getting at. Just because the one in Oblivion was called "The Society of Concerned Merchants" doesn't make it any less of a guild than say, the Dark Brotherhood. You just couldn't be apart of it in the game. Out of all those suggested, I think the Merchants Guild sounds the coolest. Something different other than running around killing things. Think about owning your own shop and hiring someone to tend the store while you're gone. When the big buyers come to town, it's up to you to man the desk and haggle over prices. You fail at bargaining, you get nothing and lose lose everything. That'd be fun.

I like the idea here. GIves the option not to be a bad guy when using stealth, without having to make the Thieves Guild all girly (Oblivion)...

Also, I like the OP idea of a priest guild that primarily concentrate on healing alchemy and perhaps some of the other skills, but have it in for healers and other types of not constantly violent classes (I know there are no classes, but it's the best word for it). Something like the temples did in Morrowind, always felt it was a shame they were left out of Oblivion.

How about a skooma dealers guild with missions that involve smuggling skooma around skyrim, dealing with addicts, taking out independent dealers etc.

The number one rule of the skooma dealers guild? Don't get high on your own supply!