Technically you are not suppose to and for the greatest safety, internationally recognized vocabulary should always be used.
However, I have noticed most heavy pilots and many controllers do a greeting. That is the difference between the ideal world and the real world. I doubt being the 65th pilot to say "good morning" improves your handling or makes the controllers day any brighter. With so many pilots and controllers doing it, it really has become a matter of personal preference.
One advantage to doing a greeting is it gives the controller a one second warning to prepare for a communication. Some aircraft are equipped with VOX (voice actuated transmission) circuity that tends to cutoff the first syllable of a transmission and a greeting gets the VOX turned on.
I believe disingenuous "thank you's" and "I love you's" dilute the meaning and sincerity of the words. If a controller really does something special (I have had two occasions my life was saved), then I use sincerity, "thanks that may have saved my life...", or "your professionalism is appreciated...".
I learned to fly from the US's second busiest airport so being brief and concise was a safety survival tactic on Saturday mornings - most pilots learn to fly from a much more relaxed environment.