Rajkumar Hirani movies-
Mix message with entertainment
Bring a new concept or word that becomes a catchphrase (Jaddu ki Jhappi in Munna bhai MBBS, Gandhigiri in Lage Raho Munnabhai, All is Well in 3 Idiots, Wrong number in PK)
Lots of comedy and lots of emotional scenes
Doesn't focus much on music- generally have average music albums (except Dunki and 3 Idiots)
Not a single flop film delievered till now as a director
Creative decline of sorts since he separated from Vidhu Vinod Chopra (Dunki was not upto the mark). Even Sanju was no great shakes.
Yash Chopra-
Is known for making romantic films but some of his best films are action or intense drama films (Deewar, Trishul, Waqt, Ittefaq, Darr etc).
Along with Gulzar he makes poetry on celluloid
Exotic locations of Switzerland with heroine in chiffon sarees in ice clad mountains
Grand sets, big star cast, brilliant music
Made films till the end of his life (Jab tak hai Jaan- not an ideal film to end career)
Karan Johar-
Feel good escapist cinema which ages really bad over the years and becomes meme template after some time (KKHH, K3G)
Made a really good film (MNIK) and then back to making mushy romantic films
Nepo kid launcher through his production house, also SRK close buddy
Shoots all his films overseas - caters to overseas market for NRI so his films earn huge in overseas particularly the ones starring SRK
Very good taste in music, very grand sets, trendy costumes and brilliant production design. And then forgets to write an engaging story (though he writes good dialogues)
Many people still thinks that he is the director of Kal ho na Ho (sorry Nikhil Advani)
Produced one of the rare remakes of a cult classic which was equal and at times better than the original film (Agneepath)
Forced homosexual humour
100% track record as a director still has directed only 7 films in 27 years.
As a director I would say Yash Chopra>Rajkumar Hirani>Karan Johar
As a producer Yash Chopra>Karan Johar>Rajkumar Hirani
Most number of National and Filmfare Awards Yash Chopra>Rajkumar Hirani>Karan Johar (7 National and 10 filmfares for Yash Chopra, 4 National and 11 filmfares for Rajkumar Hirani and 4 National and 10 Filmfares for Karan Johar)