1) Anil Kapoor. He is a highly under rated actor. He can do serious and comedy roles with equal ease. Sadly, he never got the classics that SRK and AK (Aamir) got.
2) Chiranjeevi. Again an actor who can make you cry and laugh. He was touted as the combination of Rajini and Kamal. Watch his movies like Aapadhbhandavudu, Chantabbai, Rudraveena, Swayamkrushi, Abhilasha.
3) NTR: I cannot think of another actor who can play the roles of gods and kings better than this guy. He was terrific in movies like Malleswari, Mayabazaar, Patalabhairavi, etc