I like Better than Bouillon A LOT, but I would never use it for a soup for which the broth is the key feature. It still tastes like salty bouillon, but it is pretty nice if you're making cream of brocolli or something where the bouillon flavor isnt featured.
I'm a pretty big fan of Swansons 33% less Sodium for uses that need better quality stock, but really, homemade is king.
Eat a rotisserie chicken one night, put the bones in the slow cooker over night and you have stock for egg drop soup on day 2.

Bah. Just spotted the 'vegetarian'. Same goes for vegetarian homemade stock, though. Brown up some onions celery and garlic and then slow cook with water. Easy and delicious.

This product contains sugar and Partially Hydrogenated Soybean Oil, what is that? Trans fat? A lot of bouillons contain these kinds of ingredients, in addition to palm oil. You have to read all the labels to avoid them.

Trader Joe's has a veg stock concentrate. I haven't been able to find it lately, but I loved the stuff! It is the kind that comes in the little packets and is a liquid, not powder.

I love the Better than Bouillon, but it does have a strong flavor. For a less overbearing taste, I just tried Trader Joe's vegetable stock in a carton last week, and it made a really good matzoh ball soup.

@fi_burke - some (all) vegetarians might object to a chicken-based vegetarian stock.

To answer the question, I've been making konbu dashi at home for a miso and somen soups. The basic recipe involves soaking konbu in water for a few hours, that's it! The super-tasty, can't-live-without-it version can be found in "Japanese Vegetarian Cooking".

For an everyday vegetarian stock, Bittman's One-Hour Stock is wonderful. I add in some ginger and white cooking wine to add flavor, make a double batch, then freeze.

I like Better than Bouillon and Frontier brand Chicken-flavored broth powder for soups, both at half-strength. The chicken-flavored broth words for egg drop soup, I've found, with the addition of a little soy sauce and toasted sesame oil.

Also consider Deborah Madison's books, espec. Vegetarian Cooking for Everyone and Vegetable Soups from Deborah Madison's Kitchen. She has a trick she calls quick stock where she uses the scraps from the ingredients for the soup to make a stock that adds much depth and flavor to the soup and takes almost no time.

@fi_burke - sorry for the snark, I just noticed the 'storebought'!

Really, I've never found anything in a store that wasn't loaded with crap. I'd rather spend a little time one weekend making stock to freeze than put all those chemicals in ma belly.

I really like Imagine No-Chicken broth. It's my favorite vegetarian broth to use when the recipe calls for chicken or vegetable broth. I think they also have a mushroom broth I remember liking but it's been awhile since I used it. Might be another brand.

Better than Bouillon is my go-to these days. I believe they also make a mushroom base. I usually buy the Pacific low-sodium veggie stock, but the Imagine brand is also good (and slightly cheaper). I agree with nwatrous: the no-chicken kind might be what you're after.

i like better than bouillon but it is pretty darn salty. i recently tried some medford farms veggie stock (it was on sale at my local harris teeter) and it was good - i liked that it was very low sodium.

I've been using Rapunzel brand vegetable bouillon with herbs and salt (http://www.amazon.com/Rapunzel-Vegetable-Bouillon-3-1-Ounce-Packages/dp/B001E5DZJ8/ref=sr_1_1?ie=UTF8&qid=1322751598&sr=8-1) on the recommendation of Heidi Swanson from 101 Cookbooks and it's been great so far. Not sure how it would be for miso soup. Also - she has a recipe for Homemade Bouillon that I'd love to try - http://www.101cookbooks.com/archives/homemade-bouillon-recipe.html

For Asian soups, you want a kombu dashi, or a dashi made with bonito. Instant versions are sold in packages of little paper tubes, full of granules. Each tube makes a quart of broth. If you're in NYC, you can get these at Sunrise Mart. Ask for instant dashi. Vegetarian is green. The bonito is reddish.

I also prefer Rapunzel vegetable bouillon. I haven't found a store bought vegetable stock that I like (too sweet).

I have really strong opinions regarding this because I had the same issue several years ago. I really love Edward & Sons Not Chick'n Buillon Cubes you can get at whole foods.

If something calls for chicken stock/broth putting veggie stock in just seems to ruin the recipe for me. Veggie stock/buillon is just so much sweeter and generally is too mushroom-y or carrot-y and overwhelms the dish (to me).

The Edward & Sonds cubes have a nice roasted flavor to them, which is really what I'm looking for if I would be using chicken stock. I've had great success using it.

Rapunzel brand is what i use if I am purchasing but I almost always have freezer stock made in bulk and in small cubes. Its really simple and practically free

I'm a big big big fan of the Savory Choice brand, which sells condensed stock in packets. I can find it at my local market, but I know Trader Joe's also sells their version of same. Rapunzel taste like yeast to me, and veggie stocks sold in cartons are just putrid. This stuff is the best I've ever found and it's usually cheaper than other stocks. Also, since it's sold in packets you can use only what you need, unlike with the cartons.

http://www.savorychoice.com/index.html

i recall America's Test Kitchen (i think it was them) recommending Knorr's

The best product -- for both vegetarian and meat-based stocks -- is a product by Knorr which I can't find here in North America, but perhaps you can look for it in delis. In Switzerland, it is called "Marmite", and in England "Stock Pot" (a direct translation), and so you might be able to find it in English food stores, and Swiss or French speciality food stores. Hope it makes it to North American grocery store shelves soon, because it is a brilliant product!

http://www.youtube.com/watch?v=UvZum9BCYOA

p.s. Nigella always recommends Marigold Swiss Organic Vegetable Stock Cubes. Alas, they can only be found in British stores.

Marigold is the king!

I LOVE LOVE LOVE Rapunzel vegetable bouillon with sea salt and herbs. Though they also have a low-sodium version and one without the herbs. I buy boxes of it at a time and it seems to work well in all situations, including Asian soups. Though you might also want to try a mushroom stock for a more Asian flavor.

I like Better Than Bouillon No-Chicken base and Rapunzel low-sodium vegetable bouillon cubes. I make my own dashi, however, since I've never found a storebought bouillon that works well in Asian dishes.

I really like Whole Foods brand vegetable broth.

I love Better than Bouillon Not Chicken Broth - it's a great Chicken Broth subsititute! Though I use a little less than the recommend 1 tsp to 8oz water - because it's a little salty.

I really like Better Than Bouillon, and use it quite a bit. Any Imagine broth is my second choice.

I'm sure I'm in the minority here, but I really like Swanson's vegetable broth. I use it alllll the time.

You could also try making your own vegetable bouillon:

http://www.101cookbooks.com/archives/homemade-bouillon-recipe.html

We normally buy Pacific for veggie broth, but did try the Imagine this past Thanksgiving. Not as excited about the Imagine for our uses, it was a tad thick for use as a brine base. But it would rock for soups.

Imagine's No-Chicken broth is my favorite. It's light and not overly salty in comparison to some other brands.

making your own broth is about the easiest thing there is. save your cooking scraps for a couple of days instead of composting them (i put them in a plastic bag in the freezer) and then boil the hell out of everything. i usually have a box of imagine low sodium veggie broth on hand 'just in case' but it never actually gets used.

My favorite veggie boullion is homemade. Heidi Swanson posted a version of it. The homemade boullion is pretty salty, but you can cut back on it and store in the freezer. As long as there's still enough salt in it, it won't freeze solid so it's easy to scoop.

Rapunzel all the way. It mades a great base for a lot of soups (mmm, potato soup).

This has been discussed so much on The Kitchn, they even did a review of the DIY bouillon from 101Cookbooks. I'm surprised the editor of this post did not include more links.

I'm so glad I stumbled across this thread. For years, I have been successfully using Kikkoman Instant Tofu Miso Soup in recipes that call for chicken broth. It does have seaweed and small cubes of tofu in the soup, which could be strained out, but I am more inclined to blend them in with the stick blender. I look forward to experimenting with some of these other options. I also echo the opinion of other commenters who pointed out that vegetable stock is usually too sweet to substitute for chicken stock.

Disclaimer: the Kikkoman Miso contains powdered fish.