I use a version by Organic Gourment, called Savoury Spread. It's not as salty as Marmite or Vegemite. It's yummy! The ingredients are nutritional yeast extract and sea salt. Gluten-free and vegan.
Here's the link:
http://www.organic-gourmet.com/
I also make a paste from nutritional yeast flakes and olive oil, sometimes adding a bit of roasted sesame seed oil. It's quite different from the Savoury Spread, but very nice as well.
Yeast spreads on rye toast or Rye Krisp with sliced tomato, or just with butter is grand.
I used to eat the yeast spreads on wheat toast with butter, but stopped eating wheat.
There are some other yeast spreads in Europe, too.
Grrrkgrrrl, I'm glad you enjoy them!