It's not only flowers that have smells some leaves can give off a strong scent. I like using creeping thyme (there are lots of types) to smother weeds on the cracks in pathways. It's low lying so when you step on it a strong thyme smell hits your nose. Of course not everyone is going to like the smell of thyme but I think it is great. For me it is very uplifting and fresh/clean giving me a similar feeling to the scent of the air after a thunderstorm.

The seeds are usually very cheap but you get a greater variety if you can find a plug seller.