This is really something that's been argued and debated to death so much over the years that it's never really gonna be resolved.  Nobody knows how much weight the Hulk is capable of lifting, supporting, tossing, or whatever.  One reason that Marvel eventually came up with the whole rage enhanced strength complex is to allow the Hulk to be considered in the same category of strength as characters like Superman or Thor.  The 150 billion ton feat might sound pretty high up there, but it's still pretty conservative compared to Superman during the 1970's when he was written at being able to move planets and fly through stars.   Take some of these examples of the Hulk's strength: 
 Marvel Comics Presents #52: The Hulk destroys an asteroid written at being twice the size of Earth. 
 Onslaught: Marvel #1: The Hulk cracks Onslaught's armor when the combined efforts of the Avengers, X-Men, and FF are unable to even scratch it. 
 Tales To Astonish #73: The Leader states that even with his advanced technology, he has no machine that can come close to measuring the Hulk's strength. 
 The Incredible Hulk Annual #8: The Hulk strikes the ground with enough force to shake a large section of the Rocky Mountains. 
 The Incredible Hulk #410: The Hulk takes out a prison blastdoor that is said to be able to withstand a nuclear strike with one punch.  
 It goes on and on, and of course, all of these are debatable.  Take the last one for example, can the blastdoor actually withstand a nuclear strike or was it something that's just taken as an exaggeration.  You know, like saying "That guy's as strong as an ox".