A friend of a friend of ours was gushing about a delicious “Vietnamese crab noodle soup” he just tried a few weeks back, but being a non-foodie, he didn’t write down the name, nor even remember the restaurant in Little Saigon he was taken to (by his Vietnamese friends). 
Question for our Vietnamese cuisine experts (@ns1 @hppzz @attran99 @JeetKuneBao and others):
Thanks!
Bun rieu and banh canh cua are 2 different animals. Bun rieu is a light broth and is usually made with either a pork or chicken stock base and then spiked with crab (i.e. fresh crab and/or jarred oily crab parts) and tomato. Sorry, I don’t know how else to describe the jarred stuff…I see it as a staple in my Mom’s pantry. That broth also includes large chunks of ground pork suspended in a scrambled egg soufflé…it’s super light and not at all heavy. Sometimes the crab is mixed in the egg soufflé and sometimes it’s just floating separately in the broth…or both…it depends on the cook. Sometimes there are fried tofu chunks that hang out in the broth until they become flavorful little sponges. Served with rice vermicelli and the accoutrements are more herbs, greens, bean sprouts, banana flowers, lime wedges, etc.
Banh canh cua is a much thicker and richer broth covering tapioca noodles…or what some people call Vietnamese Udon. The crab is way more evident in this dish and truly is the star. It can be garnished with crab, shrimp, crawfish, and also lobster…depending on the cook. I’m basic so all I need is a squeeze of lime and this bowl is perfect. You can find it at Ben Ngu and Ngu Binh…or any central VN specialist. I’ve also seen it at Brodard. My son had at it at Ben Ngu and really enjoyed it…but does he like it more than grandma’s? No. For better visuals, I’ve seen @hppzz ‘s rendition on their IG and it’s spectacular.
I’m going to defer to other folks on where to find the best because I’m spoiled and only eat my Mom’s version.
Mai Phung speciality is Banh Canh
Quan Bun Ban Mai speciality is Bun Rieu and Canh Bun.
Quan Bun Co Giao Thao also specializes in Bun Rieu.
Start with those. Or even better go to your Vietnamese friend mom/granny/auntie house for Bun Rieu
Thanks @JeetKuneBao! Bookmarked them. 
Have you tried the Banh Canh Tom Cua at Ngu Binh? Curious how it was compared to Mai Phung.
Sad that pho co ha noi closed they used to make a mean bun cha
Had the Banh Canh Tom Cua at Mai Phung about three years ago. Fresh crab, pork belly, shrimp, and a ridiculously tasty piece of shiitake. Absolutely splendid.
What’s the name of the noodle soup made with escargots? I believe it’s a tomato-ey based broth.
Bun rieu oc or bun oc
For my taste buds bun rieu is far superior, but I have never had one out in the wild that I loved. It’s always short on the crab meatball things.
The best one in LA proper is probably at Button Mash.
Off top of my head, In sgv there are multiple spots that serve bun cha:
Pho Hai kieu
HP pho ga bac ninh (Rosemead)
Pho ga bac ninh (Monterey park)
Bun Cha Hanoi really needs to be done properly out here. I have yet to see a charcoal grilled Bun Cha Hanoi.
@attran99 descriptions are spot on and both @JeetKuneBao recs are good starting points to explore these dishes…
As with most places in little Saigon you’ll find these two dishes on many menus just because they are really popular. However, as a general rule you’re better off trying to eat these dishes at specialist…
For bun rieu we try to stick with northern cusines specialist such as Quan bun ban mai. But often the lines get blurred and some places are just noodle specialists and offer all the popular soups…like mai phung which has a relative concise menu of soups featuring two types of Banh Canh cua, one with the annato infused slightly thick texture and one with a clear broth as well as bun rieu. So if you want to kill two birds…err crabs…
There is one Banh Canh specialist where the entire menu focuses on Banh Canh—30 different versions and that is Banh Canh que em & que anh. While most pple know Banh Canh as a crab and seafood soup, there’s actually lots of variety. We grew up eating not just the crab version, but chicken, and pork as well. So this spot has all all these varieties and then some.
We haven’t been to these locations in years so can’t comment on them now but it’s a good starting point for explorations of lesser known Vietnamese soups.
Hi @hppzz,
Thanks so much for your thoughts. Wow, 30(!) different varieties of Banh Canh?! 
Bookmarked. Although @attran99’s link to your IG of your own homemade version of Banh Canh Tom Cua looks incredible! You need to open a restaurant. 
I have not! I can’t seem to get away from Ngu Binh’s Bun Bo Hue, Ice Coffee, and maybe Banh Beo if I am extra hungry. But always Bun Bo Hue and Ice Coffee.
Growing up, Mom only ever made the chicken version. It got fancier with freshly killed chickens as we got older (and more financially sound) and was cool when it was a female with an embryo or two inside. The crab only came later in life when I made the transition to high school.
My Mom still makes both. She makes the chicken version for our kids every once and a while and the crab for me once in a blue moon.
Oh, forgot to mention, while the Banh Canh cua is known for its thick, slightly viscous rich body broth—Dac—many of the pork and chicken Banh Canh have a a clear thin—Lõng -broth. You can request either but their menu has some defaults Broken along those lines. You can actually also request different types of noodles—dai for the chewy clear tapioca noodles vs the the ones with rice flour and tapioca, which looks like the udon in appearance.
Mai Phung also has a Northern/Hanoi style Pho, Northern style crab egg rolls (these are limited, the filling is delicious! The fry can be hit or miss at times though), and Bun Cha Hanoi. I might hit up this place later in the week.
Oh yeah try the house made chilli sauce! Squeeze some limes into them. They have tableside limes btw you are gonna want to use some for Banh Canh.
