It's kind of odd, because I barely know who he is, and the only issues I have are the two-part crossover with Fight-Man.
So, in the dream, Galactus comes to Earth, and hires Deadpool to do ... something (unfortunately, I forget what). Of course, everything goes awry, and in sheer frustration Deadpool ends up beating Galactus to death!
Deadpool then goes into a complete panic, and ends up going to Reed Richards asking for help.
At the conclusion, Galactus revives and explains that he's not really killable, being made of pure energy, his human form only being the way people from Earth tend to see him.
In my subconscious, the whole thing was pretty funny, and I bet it would have made a good issue.
His legions of rabid fans will be bursting at the seams to read it!