A collection of nine brands/trademarks that are so popular that they made it to Oxford Dictionary as nouns. There should be more...

What about Kleenex?

Diesel is most common of all

Some people in the Philippines say Kodak instead of photo, Colgate instead of toothpaste and yes, Kleenex instead of tissue.

I remember Alan Partridge taking great delight in pointing out that "Tannoy" was a brand

Google too.

"cellophane" refers to a wide variety of plastic film products but was originally a brand name.
it has since been superseded by other products.

however cellophane is 100% biodegradable and is making some thing of a come back as a food wrapping.

What about "Modess"?

Hey reidenschneider, thanks! I didn't know that.

00kayi00, I'm not sure of Modess. I haven't heard anyone make use of it as a noun. I guess it counts if you know of people who make use of the brand as a name. LOL.

Another genericized trademark is Jeep!

Don't forget band-aid! And Google is a verb too

"Hoover" is only used as a generic term in England. The US still uses "vacuum cleaner" or "vacuum" and sometimes "vac". Of the items on this list, only "spandex" in unquestionably generic. The others are still registered trademarks and still defended by their owners. These are distinctions that professional writers are reminded about in trade pubs. "Escalator" and "aspirin" were once brand names, something a lot of people have forgotten.