Aamir Khan is the best of all the Khans because he can work with a first time director or a little known director and still can deliver hits.
On the other hand it is the media who has hyped up srk, a media made freak.
Well i am not a bollywood freak or anything, i don't even watch bollywood movies anymore (2-3 a year at most) but since you don't know why SRK is in the list, i should just remind you some movies ( DDLJ, KKHH, Dil tou pagal hai, Baazigar, Veer Zaara, Main Hoon na, Kal ho na ho, Chalte Chalte, Devdas, KKKG, etc etc etc i mean list of his hit movies goes on and on ).
Since i don't know much about Nana and Naseerudin (i do agree that they are extremely good actors), maybe people should name some of their hit movies???????
I wouldn't argue about Amitabh, he is definitely one of the best ever actor.
If i am not wrong almost all Khans are married to hindus including Saif, Aamir, Arbaz, Salman (most likely), Fardeen's sister etc etc
I watched one of his interviews in which he mentioned something like this
" Before i became an actor i was going through very tough times, my mother died, i wasn't doing too well financially and i was about to get married. I had no idea what to do and one day i was walking in the streets of Mumbai and in frustration i shouted " Aik din mera is Mumbai shehar pe raaj hoga" (I will rule Mumbai) and i think he has pretty much done that :) :) .
What i mean to say is that things didn't work out for him just like that, he worked hard for it and earned the fame with his unique acting style which wasn't highly impressive in the beginning but he improved a lot with time.
Nana has done romantic roles where the script of the movie required him to romance.
Remember the scene from Taxi where him and his wife are lying on the floor and he wants to have sex while she doesnt.
Then there was another movie of his where he finds his wife cheating on him and then kills her.
First part of the movie was basically bout him and his wife in the movie.
Plus Nana's role in that movie starting with a Y with his famous line, 'aik machar sala admi ko heejra bana daita hay'
He and Madhu (i think) were married in the movie and they showed their married life in it too.
True he's not the one who will run around trees and sing romantic songs and break into dance numbers but if the script requires he does romancing too and kinda looks very cute