Being one of the few people who really doesn't care for the first "Grease" I must say that "Grease 2" is better than the the 1978 original.
Does it make it a good film? Not necessarily. But at least its entertaining and oh so quotable.
Sure, the songs aren't as good and its a lot sillier but at least it embraces its stupidity. Also, the plot is understandable (and not as morally questionable), characters likable and musical numbers energetic. Plus Michelle Pfeiffer & Maxwell Caulfield are more awesome than Olivia Newton-John & John Travolta.