Flowers
It is obvious, hackneyed and old fashioned to give a lady flowers, but guess what? I have only ever met one woman who didn't want to receive flowers.
She owned a flower stall!
For the rest of the population, being given a bunch of flowers is still a welcome gift.
Size is important. I repeat, Size is important. A large bunch of flowers is the equivelent of shouting loudly in the streets that you think she is smashing. If she is a shy woman then a more understated bunch might be better.
There are also bits of symbolism related to some flowers which many men miss. We all know that roses are for rmoance, but a gift of lillies (traditionally given at funderals) may offend some women.