Amplitube ... if ihad to keep one it will be it ....(amp sim not specially bass amp talk here) , it is simply unmatched , purist will talk witch one is the closest ect .. regular tech talk , but at the end , i trust my experience , and believe me when i'm in the primitive side of production dropping instant feelings ....i reach to AT , not because i know it better than others , simply because it always leeds me to the results ....