Narrative Opening with titles running throughout.
A example of this would be Panic Room, the sequence involves a helicopter that flys over new york city showing the setting of the film as well as cleverly blending the titles into the city with names of directors and actors ETC appearing on the sides of buildings and vehicles.
Discrete Title Sequence.
Such as Se7en, a discrete title sequence means that the title sequence is a short self contained film in its own right and has little or no relationship with the main feature film or is showing a part of the film irrelevant to the real opening, in seven the sequence uses very dimmed and distanced lighting as well as only using extreme close up camera shots to create a intriguing and suspenseful intro.
Titles over a blank screen - followed by a narrative opening
Stylised Edited Opening
A stylised opening to me is one that makes heavy and effective use of complex editing techniques, a excellent example of this is the taking of pelham 123, in the title sequence of this film (which can also match structure of narrative opening with titles running throughout) initially only a discrete style sequence is used with images of trains moving as well as the tracks and control room being shown in various angles and styles and speeds, then titles start to begin to appear near characters which freeze as there name travels in with the font moving like a train, pausing, and then moving away horizontally as the characters begin to move again. As the sequence progresses elements of the main film begin to come into the sequence with the end quarter of the titles progressively moving into the actual story.