How about white ginger? Hedychium coronarium. Love that scent! I also like Jasminum sambac, either the grand duke or the Maid of Orleans.
kevin

double pink or double yellow nerium oleanders will give fragrance during summer months. Jasmines will also add to the fragrance.

I agree with Kevin : By all means add a Jasminum Sambac to your garden. Other Jasmines will too do reward you with overwhelming scents at night. Mine are indoors (I live in a flat with just a north facing window), and grow light are doing wonders :

Can you imagine Tonight, just by my side : Over 85 flowers opened together on the same plant (a jasminum Nitidum - star jasmine)

Guess how powerful the perfume is !! Not to mention over ten flowers of J. Sambac (double flowers) in the meantime !

What a lovely night !

Fragrance is the major reason of my gardening. They must have a nice fragrance then I will start considering other factors before I choose to buy one and stick in my yard unless it has the significant quality. Right now I have a trellis by a front door all covered by star jasmine and I am in heaven too!

My yard smells like this in the following order:
Daphne (Abour January-February)
Sweet Olives
Freesia
Daffodils
Honeysuckle
Citrus
Louisiana Phlox
Iris
Angelwing Jasmine
Sweet Williams
Gardenia - Veitchii
Star Jasmine
Peruvian Daffodils
Arabian Jasmine - Grand Duke
Jasmine Sambac - Maid of Orleans
Night Cented Jasmine
Butterfly Ginger
Tuber Rose (About October)

Almost throughout a year:
Rose
Sweet Alyssum
Lavender

I need banana shrub, wisteria, fragrant almond, magnolia and more gardenia & jasmine. I need more land, actually.

A very good garden of eden !

Tonight this is it : my Sambac 'Grand Duke' just have opened his first flower, looking like a mini rose, pure white and super strong sweet scent. it measure 3.5 cm in diameter ! wish I could have many of them together !

This is really a holly flower !