Trade names which are almost synonomous with the generic product

Velcro

Good shout HHSV

Aspirin

Thermos

Zip

Is Aspirin a trade name?

Actually, surprised you didn't say Guinness

Sellotape
Xerox

Well you don't ask for a particular aspirin, soooo.

Thermos and zip are good shouts although I thought that zip was now ok to use as the product name

I spose i should have said zipper..

Jacuzzi
Yo Yo

Durex (probably more true in the 70s and 80s)

Great examples Alpha. Didn't even know Jacuzzi and Yo Yo were trade names.

JCB

Sellotape

Viagra

Plasticene
Play-Do

Biro
Valium

Blu-Tac
Post-It notes

Stationery's full of it...

Milk

Jeep?

Coke

Google; although the verb "to google" has now been included in the English language

Betfair, as in meaning to "bet fair".

Not really sure though.

Anusol.

Cream relief for your 'chalfonts'

Spoilsports
VISA

Not really a trade name, but whatever fuel is used in an engine started by compression gets named after the engine's inventor, Rudolf Diesel.

Herr Diesel himself used coal dust or vegetable oil, but these days fuel derived from petroleum, gas or wood all gets called diesel.

Then there's Amelia Bloomer, the 19th century American feminist, and Antoine Sax, the 19th century Belgian musical-instrument maker.

Coke

wallis   13 May 14 15:14 

Anusol.
Cream relief for your 'chalfonts'

I have always referred to suppositories as bum pellets. The other half was going to do the shopping a year or two back and I told her to get me some bum pellets whilst there. So she got to the pharmacy counter at Sainsbury's and couldn't remember the real name of them as she was only used to what I call them. "Can I have some bum pellets please?" she had to ask, very embarrassed. Fortunately they understood her.

Filofax