This response comes from a not very young, rather old-fashioned Englishman. My generation was not brought up to give, or to know how to accept, compliments.
For me, "I really enjoyed your lectures" or "Thank you for your very interesting lectures" would be fulsome praise.
Anything more than that would be embarrassing for me to say, and excrutiating to receive. Let's hope some younger members will give you some gushier ideas.
Student or Learner