Kensington fly sheets are the absolute best ! They are a bit pricey, I buy mine on ebay
. They hold up really well. I had one for 3 years [that I sold only because my horse out grew it] and it still looked brand new.
I like saxon blankets if you are looking for something cheap. Or weatherbeeta if you are ok spending a bit more. I don't like schneiders because they give my horses really bad rubs.