Although critically maligned, Johnny Dangerously is one of the funniest movies I've ever seen. It's a movie that should be watched closely; some of the funny bits are done in passing and do not have the usual amount of attention drawn to them. For instance, keep an eye on Michael Keaton's use of the pricing gun at the pet store...and also on the documentary-style years that appear at the beginning of scenes. It's one of those rare movies where the humor hits you unexpectedly, even though you know it's a comedy. Amy Heckerling, the director, is really sharp here--If you enjoyed her better known films (Fast Times at Ridgemont High, Clueless, European Vacation, etc.,)you should give this one a look.
Michael Keaton is extremely likable in the title role and the supporting cast (Griffin Dunne, Maureen Stapleton, Joe Piscopo, Peter Boyle) is excellent. Highly recommended.