I prefer percale sheets, which feel crisper and coooler to me than sateen shits, which are silkier.
I don’t really pay much attention to thread count, but they do have to be 100% cotton.
One advantage to white sheets is that you can bleach them. I have a few different brands.
This may be a bit US-centric, but that’s where I’m located and the brands that are available to me:
at Target:
Threshold brand percale sheets. These have been good, but weren’t available last time I was looking.
So I got TriBeCa brand percale, also at Target. They are OK, a bit thinner than the Threshold and didn’t seem as sturdy.
At Amazon:
Peru Pima percale: these have been my favorites but are also the most expensive. A little under $100 for a queen set.
A close second is Pinzon percale at Amazon. Almost as nice the Peru Pima ones and half the price if you catch a sale.
I read reviews that said LL Bean’s percale sheets are also very good, but I think they are around the same price as the Peru Pima.