Rio has nice views of Strip, but I have usually had luck just by asking nicely if there is anything better for what I am already paying. Not trying to be stingy - I did try the "$20 trick" one time, and the person at the desk just took the bill without doing anything at all - person was not obligated to do anything, but other times I have just had person at whatever hotel just give it back to me if there is nothing extra they can do.
