Shah Rukh- Salman
As far as boxoffice is concerned SRK and Salman gave 17 Hits in 1990-1999 where as Govinda and Sunny gave 15 Hits in the decade.
SRK and Salman gave 25 Successful Films where as Sunny and Govinda gave 26 Successful Films.
Sunny and govinda.
Obviously srk and salman.
Top 4 grossers of 90's
In terms of hits govinda and sunny had 1 more but the atbbs were given by srk-salman.who can forget their deadly combo with karan arjun