I think you mean by the best budget mobile which is used by others, I am using Nokia 3110C which is a mobile with a 1.3MP camera, music and media player, expandable memory upto 2GB, lots of contact storage space all came for a highly reasonable price. If you want to know more about that mobile and its features click on this link Nokia 3110C
I am using Nokia 3230 which is with me nearly 3 years. For budget plan, u may purchase a second hand one. Its easily available with Mobile shoppers itself. In Delhi, Karol Bagh is a good destination for all brands. Else, u can go to Chinese one.