Hi guys

I currently own a pair of cheap nasty sunglasses with interchangeable lenses, which have seen better days.
I have a problem in that most sunglasses I try on seem too big and make me look like something from a sci-fi film! The fit might be ok, but the actual lens cover half of my face!
I'd preferably like the changeable lenses as I want them to be good "all-rounders", but would prefer a nice trade off between style and price. I'm not prepared to spend a month's wages on something I'll scratch.
Can anyone recommend any personal favourites? What brands or models are better suited to a smaller sized face?
Any help would be gratefully appreciated.