There are several gang type guilds that operate out of Gilneas that I’ve heard rumour of although not having RPed up there yet the only one I know of is the Blackwood Syndicate. Similarly I believe Booty Bay has a small guild or two as well.
The newly minted Gilded Dagger community has a fairly good representation so far as well.
In Stormwind I’ve seen a few guilds running criminal activity, and with a shameless self promotion, my own the Guild of Thieves. We try to encompass most criminal activity from the lowliest beggars and pickpockets to the most highly skilled, debonair con-artists. Send me a message in game if you’d like to know more.