Next to Sridevi, Rambha was by far my favourite Bollywood actress. She wasn't a particularly GOOD actress last time I checked, but she had genuine spunk, a terrific turtle-nose, a strangely genuine screen presence, and WOW she could dance. For these reasons I think of her as India's Ann Miller, always likable but rarely the "star."
To illustrate this, here's one of the few good numbers from "Beti No.1." Rambha is the only person who can out-dance Govinda, and in this song she effortlessly matches him move-for-move.