I like a tone on tone white. It takes away the sharp plain white look and adds some texture to my background.

Kauffman's Kona cotton is nice. The quality of muslin really varies but some is nice very nice. I also got some plain white yardage at Connecting Threads that was very nice, but I'm not sure they always have solids at their website. I wish now I'd gotten more.

I just bought a Moda white that was fantastic.

I know it is a bit more expensive but it was worth the extra cost.

Nettie

Bleached muslin , white on whites. Really - that's all I ever use. I buy Kona solid colors - but muslin is really my staple. Remember - you are going to have batting behind it. It will not shadow through. And there are some really nice "quality" muslins out there. I've never had a problem with them. The age of some of my quilts can prove that.

That what I do and I love it!

Ditto on this. Not sure I've ever bought a plain white.
There's white, and there's white, too.
winter white
bright white
soft white
off white
............

I just bought the Moda solid white, and I like it a lot. It is quilt shop pricing, though.

For a lower price, I'd buy bleached muslin.

Southern Belle feels great. Love it.

I love Kona fabric. I found some white on white at Hancock Fabrics. It's one of the few whites that called to me.

Buy a tone on tone. They add more interest than a solid white and generally are a better quality. You can buy different shades of white-cream. Sometimes an off white looks better than a real white. Personally I prefer the off white for my scrappy quilts.