I knew that. That’s what happens when I’m posting pre-caffeine.
Preach it brother! I’ve been going to the same Thai place for over 26 years (we’re now on first name basis with the owner) and while I spent decades eating Thai hot, in the last 5 years or so I’ve gone down to merely “hot”. I can still eat and enjoy Thai hot, but as you say, I do so with full knowledge of digestive consequences down the road.
My preferences is on the highly spiced, often sour/funky flavors. So Tom Yum Goog (Tom Yum soup with prawns) is a must for me at any new place (if it’s small enough for me to eat, my wife won’t). Any place that makes it in a dedicated broth with rendered shrimp shells is going to get a major +1 from me.
I’m also a major fan of the Thai Garlic and Black Pepper combinations - they don’t highlight the skill of the chef in the same way more complicated (or subtle) dishes do, but anytime I can combine the pungent spice of fresh black pepper, garlic, and capsicums, well… I’m a happy boy.
A good Pad Thai is a thing of wonder, but almost every place that does them errs on the side of too sweet, and that is right out for me.
My other favorites are sadly not on this menu. I’m a huge fan of Yum Neu/Nau or Larb Neu/Nau, which is thin strips or chapped of beef, seared, and served on a bed of greens, tomatoes, and cucumbers with a tangy, lime heavy hot and sour sauce including a noticeable amount of fish sauce.
Sadly, about 1/3 of the places I go add too much palm sugar to the sauce, and it comes out far too sweet. I want a hint of sweetness, but it’s the sour - hot - lime - funk I want to be tasting there. These are especially good on hot days and during early to mid summer (region permitting) it turns up to 11 because all the greens are fresh and their flavors are peak.
My toes are curling and I’m holding back drool. Dammit.
Many thanks for all the replies!
I’ll let you know how good the food is when I try it (I’ll probably wait for some reviews first…)
Pad see ew hold the broccoli.
I don’t have any useful advice or recommendations, just an anecdote. My parents and I used to visit my older brother in Manhattan from time to time, and he’d take us to one of his favourite Thai restaurants. He’d order for all of us from the stuff that he knew was terrific, and what an experience that was!
If yours is anywhere near as good, I’m envious!! Enjoy! The main difference is that you won’t have my brother around to pay for everything! 
I really prefer Chinese broccoli in pad see ew - the extra bit of bitterness and texture balances out the soft, slightly sweet noodles. But even near me (where Thai restaurants are everywhere) regular broccoli has kinda become the default. Sad for me, but I thankfully I still like regular broccoli.
In terms of soups, I’ve always preferred the comforting richness of Tom Kah (made with coconut milk) as opposed to the clear broth Tom Yum, but I’m not seeing that as an option.
ETA: Honestly I think Masaman curry is generally the best gateway drug to Thai food. Generally not too spicy for novice palates, but a nice rich flavor. It’s not my favorite these days, but it worked really well as an intro back in the day (helped that I had a pretty good version my first time).
Thai in the UK tends to be neutered, so having had real good Thai a long time ago in a restaurant in Reading (which moved to Ireland), I’ve struggled to ever have anything vaguely authentic since in the UK.
A bunch of foreign cuisines in some countries just aren’t allowed to be as good as they should be, in the UK it’s Mexican and Thai. We’re a people who think they can deal with good authentic foreign dish, but we’re as conservative as a Grandmother with those two cuisines. It varies by countries too, depending on immigrants, French Indochina meant French speaking countries and nearby tended to get a lot of those immigrants. Thus one of the best Thai meals I’ve eaten was in Brussels. For Brits it was Indian food, but dear god, never ever eat Indian food in Germany. It is vile. Local tastes has made it salty and tasteless.
As others have referred to here, a test of its mettle is the heat of the curries. They should be hot. If you ask for hot you should get vindaloo hot. I’m not really a pad thai fan, so I can’t tell if the UK version is authentic given its not got the heat issue.
But there’s a decent chance that it won’t be authentic, and you take what you get and enjoy it. They can be nice, just how UK mexican food can sometimes be tasty rather than just mince in a wrap bulked out with rice and lettuce. But when someone suggests Thai in the UK, it fills me with the same dread of disappointment that Mexican food does (having said that there was a nice Mexican place in Bristol, not SW US good, but a lot better than I’ve normally had).
My Thai food favorite is Holy Basil Chicken, sometimes called simply Thai Basil Chicken. It’s Thai name is variously spelled things like “Pad Grapao,” “Pad Kra Pow,” etc., sometimes with a “Gai” thrown in somewhere. Minced or ground chicken stir-fried with garlic and shallot, chile peppers, and… holy basil of course.
Usually served with rice and a fried egg, it also makes for a great taco filling.
(I think I’ve changed my lunch plan for today.)
If I can stick a question onto this one: How do you convey to a Thai restaurant that you want your dish mild? As in, mild by Midwestern American standards and not That standards. Seriously, the good people who make Pace Picante Mild Sauce have a much different definition of “mild” than I do, and that shit sets my mouth on fire. I imagine the Thai definition of “mild” is even spicier.
I wonder if “so mild you can feed it to a baby” gets the message across?
Many Thai restaurants (at least in the US) will let you order on a scale of 1 to 5. You can (depending on the dish) even ask for a 0, or explicitly say no spiciness at all, or ask for the spice powder on the side so you can drizzle on just a tiny tiny tiny bit yourself (it’s very potent stuff if they use thai chilis).
Even if they normally don’t use 1 to 5, you can often say “very mild, like a 1” and the waitstaff should be able to interpret that for you to the kitchen, or let you know if the dish can’t be made that mild. That’s assuming they speak English reasonably well and is a restaurant in a Western country. I don’t know how you’d do that in Thailand proper.
Here where I live, some of the Thai food trucks won’t even let you order more than a 2 if you’re white and aren’t a known repeat customer 
They’ll just tell you straight up, no, you can’t handle a 3 and we don’t do refunds, so you get a 2 and it’ll be plenty hot. Next!
Which is to say, they know to adjust the spiciness for their typical clientele. The spiciness levels are not calibrated across restaurants or especially across regions. A 3 in one place may be much spicier than a 5 elsewhere. But a 1 anywhere shouldn’t be that bad… fingers crossed.
It is. But if you tell them “no spice - I really can’t handle anything that even registers” will get the point across. The heat really is a separate ingredient, so they can leave it out. That’s one of the really great things about Thai - while I like the heat, the ingredients themselves are so flavorful that they can stand on their own.
My go-to dish at any Thai place for me to judge whether they’re any good or not is a simple, straightforward, and delicious one:
Spicy Thai Basil Fried Rice
Gai Pad Kaprow (or it goes by any of a number of transliterations.)
As for getting it mild, I find that saying “mild” works fine for most restaurants. My problem is not convincing them to make it mild; my problem has always been to convince them that I really do want it Thai spicy. There’s two places I’ve been to that have been able to do that on my first trip there. I’ve even gotten to the point to saying “Thai spicy, ped ped”, and that usually helps.
Furthermore, I’m not the biggest fan of coconut-based curries – they’re too rich for me in general – but I’ll have a massaman curry from time to time.
I’ll have to try this next time. Ped ped ped ped mak mak mak mak? (Hot hot hot hot, very very very VERY much)