My memories of attending lectures during my undergraduate degree are fading fast, but I do remember three distinct types of lecturers who used to particularly get my goat:

(1) The Bore - Stands up the front and reads 32 PowerPoint slides word for word. Shows no passion or enthusiasm for the class they are teaching. Regrettably all too common. On the other hand, the Bore is useful because you can safely skip class altogether and just read through the lecture notes in 15 minutes at some later date.

(2) The Rambler - Has slides and/or notes, but ignores them almost completely. Has a tendency to go off on irrelevant tangents and recount "amusing" anecdotes for 40 minutes of the hour. Will typically randomly skip forward and back between slides because their points are covered out of order. The worst ramblers verbally contradict what's written in the notes and then remind you that "all lecture material is examinable".

(3) The Puppetmaster - Believes that students need interactivity to maintain attention span and maximise learning. Unfortunately, their definition of "interactivity" means trailing off in the middle of every third sentence hoping that a student will ...? (fill in the final words). The awkward silence each time as the lecturer waits for a student who isn't asleep/hungover/playing Solitaire on their laptop destroys the narrative continuity of the lecture and leads to acute embarrassment for 70% of students.

It might seem callous, but as a student all you really cared about was making sure you had enough information to pass. From this perspective, Powerpoint was fantastic because it was almost guaranteed to contain information which would be examined later.

The very best lecturers did just what James suggests: They provided all key information up front in the Powerpoint slides and then augmented this with more detail in their talk. Examples strengthened the points being made by including 'volunteers from the audience' or more general audience Q&A session.

This meant two really big benefits: lectures were still worth attending to get a deeper understanding of the subject, but the basics were all in front of you, on paper.