I think your request is a bit too vague! What sort of scarves, budget etc. I am a bit scarf person. My preferred scarves are silk or cashmere. The cashmere ones are more practical - pretty, sure, but really about keeping me warm. The silk ones vary and some are also keeping me warm and others are purely decorative.
Etsy have some lovely sellers doing lovely silk scarves with beautiful designs that I buy as gifts sometimes. I have used this store but there are plenty. Consider if you want silk or what I think of as satin - I've got a few satin feel scarves as gifts and while they're usually very beautiful, I find them a bit irritating to wear.
I have bought cashmere scarves online but I find markets are often great for good cashmere scarves, especially if you want them lighter weight.
Accessorise often does a surprisingly good selection of scarves, including smaller ones that are nice as accessories.
Department stores tend to also have good selections, but again, depends on what you're looking for.
If you want cotton scarves, stores like White Stuff, FatFace, Joules (in the past), Oliver Bones etc tend to do a good selection, with a nice variety of patterns and prints.
Of course, you can also go super posh with a liberty scarf. I don't have one of these yet!