Well, what is Om Shanti Om about?  The usual hindi formula?  

Two guys are in love with same girl, one guy dies.  Or two girls are in love with one guy, one girl dies.

Or guy meets girl, both like each other, but parents are against each other, and then something happens which lead to total reconciliation or the guy and girl die while the families regret.

Or two guys are friends, they meet two girls who are also friends.  Friends hook up with friends.  That's about it.

Or one rich guy falls in love with an average girl who is actually already hooked up with another average guy.  The rich guy uses all his money and charm to win the girl over.  Seems like he is winning because now the girl dumps the average guy and hooks up with the rich guy.  But suddenly, the average guy somehow becomes rich too.  He uses his new found wealth to ruin the previously rich guy.  His old girlfriend becomes hissa budhi khiss daat.  The newly rich guy manages to find a rich girl who has the heart of gold.

Well, there are few more formulae, but these four probably covered 90% of the plot twists in all hindi movies.

BTW, why do I find Salman Khan acting like monkey in all his movies.  And Sahrukh Khan has same bloody acting in all of his.  I like Ajay Devgan much more than those two Khans, but he is also surly and depressed in all his movies for some reason.  Now, Amir Khan, he is something else.  I like most of the movies he is in.  As for female actors, I can't think of single Indian heroine worth mentioning, nah, not even that Rai-ni.