In my opinion
Anjali
She started her career in the now critically acclaimed kattradhu Tamil M.A. Although her role was very small ,she was able to shine in the limited screen time with her charm.
She then gave another solid performance in Angadi Theru , a reflection of how the shop workers of popular retail stores are being treated.
She then gave another good performance in Engeyum Eppothum for which she earned several awards too.
Unfortunately,she was in a period where heroines were only as useful as background extras in tamil cinema and they only concentrated on who shows more skin and who is the fairest looking. Even actresses like Hansika Motwani,Amy Jackson had a long career in tamil cinema.
She tried to change tracks by doing glamour roles in movies like mangatha, kalakaluppu and Settai but it didn't suit her. In fact , the reviewers took an extra paragraph to mention how ridiculous she looked as an English news channel reporter in Settai .
Then she got caught in a controversy where her stepmother complained of her getting kidnapped only for her to counter that they were misappropriating the money she earned .
The current audience is now looking forward to dusky actresses like Aishwarya Rajesh, Sai dhansika etc who look like a normal Tamil girl instead of a north indian import.
Had Anjali been in this current era,she might have had better success due to her simple looks and natural acting.