When we first met, I told him that he was NOT to buy me (1) stuffed toys (2) knick knacks or other useless dust collectors and (3) fresh flowers. Especially flowers.
I dislike them mostly because they die (omg depressing) and go smelly, and at the end of it you have a stinking slimy vase to wash up. Hardly a nice gift, in my opinion. Live plants, on the other hand (especially bromeliads, which I adore) - all good.
Funnily enough he has an aversion to the fresh flower thing as well, mostly because flowers are often, for men, a gift of apology or guilt. Not always! But (apparently, according to a few men that I've talked to about this) certainly seems to be the case on a fairly regular basis. So I'd rather he not buy me something that has negative associations for him, either.
...so he buys me bath bombs.
Every now and again, he comes home with a big bag stuffed full of Lush bath bombs. A baggy costs about the same as a bunch of flowers anyway... and I get much more enjoyment from it. I love that man! :D