I used to grab all of Connecting Threads blenders but they kept discontinuing the colors and the fabric started to get real fraying so quit. Found Maywood's blenders were very similar in shades of CT's so started grabbing them. Of course you can't go wrong with tone on tone whites, whites on beige or beige on white so buy those by the bolt. Haven't been buying fabrics since late 2018 so haven't been keeping up with what's out there of late. Have way too much to use up before I can start collecting again and by then I'll be way too old or can't afford how high the prices for fabrics have gotten up to.

I really like Northcott's Toscana line of blenders. Some subtle mottling - I use them almost exclusively if I don't have what I need in my stash.

I mostly like whatever is the right color and on sale. lol

I agree, Grunge is great. Can you believe I avoided it for a while because the name was a turn-off? The first time I bought some, I was sold.

I don't buy many blenders. My preference is for small print fabrics, which usually means reproduction fabrics. The only time I end up with blenders is when I'm buying fabric for the Bonnie Hunter winter mystery, because I am usually focusing on color when buying for that quilt.

I love the Northcutt blenders. One of the lines is Gradations. They fray a little more than some fabrics, but the sheen and color is worth the bother. My favorite solid black is Northcutt, too. I don't currently have a black blender. Quilted Twins had a Northcutt one I liked, but it sold out before I ordered.

Maywood Shadow Play and Grunge

Ditto. I love tone on tone. I like the added texture it gives. I don't do subtle very well, so I've often used prints as blenders; polka-dots, stripes.
I don't know that i have a go to brand/ style, but i would agree with others that grunge is a FABULOUS looking fabric for blenders.

I’m probably going to sound like an idiot here, but what exactly is a blender? From some of the answers I saw here, I’m guessing it’s an “almost solid” or “tone on tone”?

If that is the case, other than white or black, why would you have a favorite line of fabric? Wouldn’t it depend on the color needed for your project?

SuzSLO, I would say 'almost solid' or 'tone on tone' is correct.

Different manufacturers produce their own signature blenders -- there are scroll types, mottled types, textured solids, etc., which is nice because you know what look you're getting when you order a Grunge, a Toscana, a LB favorite, etc. Most of them come in a variety of colors. We naturally settle into ones we like the look of and that work well, but in the end, I find that it does come down to which one is the color I want..

You are partially correct.... Blenders are usually tone on tone, or have tiny prints that don't stand out. They're usually used for backgrounds or to compliment the louder, more vivid prints in a quilt, and in my opinion because they add texture, they're much better than plain solids, which to me look flat and boring.
Yes, color depends on what's going on in the project, but most blender lines are printed in a rainbow of colors. My favorite is Grunge because as I stated earlier, I'm not a fan of girly, swirly, flowery prints. Grunge is definitely not girly, but it has a lot of texture. I know that if I look specifically for Grunge prints, it's highly likely I will find a color that will compliment and enhance my project, and add texture and visual interest. There are a couple of shops near me that carry almost every color of Grunge.