HP DJ 6940's are excellent, used 2 on a contract job I did, excellent gadgets and network well on Server 2003, they are quick and can take a photo ink cartridge as well if you want, so it does two jobs in one! HP Business Jets are also good (again ink)
Laser, black - Samsungs are fine, never had problems with them, or baby HPs but they can be a bit plasticy and fragile
Colour - Samsing again, and they have a 5 year warranty offer with them unitl end of July so you cannot go wrong really as I only expect 5 years out of a printer then if it lasts longer its a bonus really.