You might want to research the different types of Hoya plants.
Certain types of hoya are pretty floriferous. Hoya lacunosa is one that is fragrant and seems to bloom frequently for people.

However, most plants only bloom during a certain season and won't bloom continuously, especially indoors, so your best bet for constant fragrance may be to try growing some herbs on your windowsill. Basil can be grown indoors pretty easily.
Rosemary plants aren't the easiest to grow indoors but it seems like some people can do it.

This post was edited by summersunshine on Sat, Sep 20, 14 at 12:01