2. Batman & Sherlock Holmes
In the realms of ridiculous comic book crossovers, this one really takes the cake; Batman and Robin end up travelling to the UK to stop Dr. Moriarty's evil plan, at which point they come across a decrepit, old Sherlock Holmes, who going by most calculations would be around 130 years old at the time. Granted, if they were going to make a movie of it, we'd want to see a younger Sherlock Holmes teaming with the Caped Crusader, because, frankly, the idea of Robert Downey Jr. sharing the screen with Batman is just too irresistible to pass up. While the comic version tries to be "realistic" by having Batman talking to a geriatric Holmes, would most people really have cared if Holmes had just been his regular middle-aged self? I don't think the sort of audience that would buy into this crossover in the first place would really care about things like age and time...