Part 2, a bit late...
Indian food... good Indian food is all over Dallas. Probably my favorite is Sigree, at Belt Line & Midway in Addison. They have a huge menu with lots of choices including a sizable amount of Indo-Chinese food. Other good places include Mumbai Grill at Preston & McCallum in Far North Dallas, India Chaat Cafe at Preston & Frankford in Far North Dallas, Mughlai Fine Indian Cuisine at Alpha & Noel Road in Far North Dallas, Curry Bliss at Coit & Belt Line in Richardson (this one is entirely vegetarian, and absolutely fantastic... their paneer is to die for), Maharaja Indian Restaurant at Coit & Spring Creek in Plano, and several others. If you want a buffet, I recommend Vindu at Frankford & the Tollway in Far North Dallas or Chennai Cafe at Preston & Gaylord in Frisco. There's a huge Indian community in Irving with lots of restaurants, but I can't give any specific recommendations because Irving is pretty far from where I live and I don't really go to that part of town.
Nepalese food... yes, we have Nepalese food! If you're not familiar with it, their specialty is a kind of dumpling called momos, and they also have a number of curries similar to Indian food. Most of the Nepali restaurants here are in Irving, which again I don't really go to, but there are a couple in my neck of the woods. Everest at McDermott & Custer in Plano is amazing, and I'm also fond of Momo Magic and More at Coit & Plano Pkwy, also in Plano.
Ethiopian food... most of it is clustered in the Lake Highlands area around Forest & Greenville or in eastern Richardson around Buckingham & Jupiter. Unfortunately, it's been a few years and I haven't dragged myself out that far east in ages so I don't remember the names of any specific restaurants, but you should be happy with anything there. If you're not willing to go that far, there's Queen of Sheba on Inwood Road in Addison just south of Belt Line and Shebelle at Preston & Campbell in Far North Dallas.
West African food... I'm not too familiar with it, but there are a couple of places: Afrika Fusion at the Tollway & Haverwood and Aso Rock Market at Frankford & Midway, both in Far North Dallas.
Mexican food... Dallas is full of great Mexican and Tex-Mex, unfortunately the best of it is all south of I-30, which is waaaaaaaaay far from where I live (I have been told to specifically look for places on Jefferson Blvd), so I don't get to go there often. My favorite place near me is Don Pepe's Rancho, which just moved into a new location at Arapaho & Hillcrest in Far North Dallas. Another excellent place is Gio's Taqueria at Trinity Mills & Marsh in Carrollton. It also feels weird recommending a chain, but you have to try the queso at Torchy's. It's not an authentic place, it's a chain from Austin, and their tacos are overrated (not bad, just overrated), but the queso is to die for.
Other Latin American food... for Peruvian food, I'd recommed Tineo Peruvian Cafe at Arapaho & Custer in Richardson. For Colombian, I'd recommend Casa Vieja at Belt Line & Josey. There are a number of Salvadorian restaurants that serve pupusas, and I remember ordering from one once and loving it but can't remember what it's called for the life of me (I tried searching Uber Eats, but it turned up more places than I was expecting). There are a couple of good Cuban places at Josey & Trinity Mills in Carrollton, including Cuba Bella Cafe and Cuban Dulceria International Bakery. I've heard good things about a couple of Venezuelan restaurants but haven't gotten to try them yet: El Arepazo Vzla at Midway & Trinity Mills in Carrollton and Big Yummy at Midway & Keller Springs in Addison. Good Latam fusion places I'd recommend are E.B. Latin Bistro at Park & Midway in Plano and Latin Deli. Latin Deli is a local chain with a number of locations around town... I always ordered from the one in Addison Circle but Google says it's closed now, though Uber Eats says it's still open. The one at 15th & Custer in Plano should still be open though, and they have fantastic sandwiches from all over Latin America including Puerto Rican-style tripleta, Peruvian-style butifarra and lomo saltado sandwiches, Mexican tortas, and more. And I might as well mention it here even though it's not strictly Latin, though it's from the part of the world right next door: we have an excellent Jamaican restaurant in the Island Spot at Midway & Trinity Mills in Carrollton (if I knew more Jamaican places, this probably would be its own paragraph).
Mediterranean food... we've got a lot of it here. There's a _huge_ cluster of Middle Eastern places in Downtown Richardson on Greenville. If you want a buffet, I'd recommend Afrah at Greenville & Belt Line or Ali Baba at 75 & Campbell. Our most authentic Greek restaurant is Zorba's, at Preston & Plano Pkwy in Plano. It blew my mind when I went there. And even though it's a chain, we have a number of Little Greek locations that have really tasty gyros and falafel.
German food... it's Texas, we have Germans here. The king of German places in Dallas is Bavarian Grill on Premier just north of 75 & Parker in Plano (that whole area is a nightmare to navigate). It's expensive but well worth the money. For someplace cheaper but with a less impressive (but still tasty) menu, there's Henk's near Northwest Hwy & Greenville in Dallas. The best thing about Henk's isn't the food menu but the attached German and Dutch food mart, where you can buy a lot of nifty goodies. Yes, German and Dutch, they have both... including a whole rack of Dutch licorice which had me feeling like a kid in a candy store (yes, I love salty licorice, it's an acquired taste but oh so good once you acquire it). And though it's not strictly German, we have an Austrian restaurant too, Jörg's Cafe Vienna at 15th & K in Downtown Plano (keep in mind that it's run like an actual European restaurant, which means their hours are really really wonky, make sure to look them up if you go there). And of course, if you're comfortable with crowds, don't forget to go to our Oktoberfest celebration at Addison Circle in September, supposedly it's one of the biggest ones outside of Germany.
Other regional American foods... our single best New York-style deli is Deli News at Preston & Campbell. There's also a local chain called Cindi's, with several locations all over, that's not bad, but Deli News is way better... except for the matzo ball soup, Cindi's is unbeatable at that one. We have a number of decent Philly cheesesteak places too, with two local chains that are really damn good: Texadelphia and Fred's Downtown Philly. They've got a handful of locations. For southern soul food, I'd recommend Trucker's Cafe at Arapaho & Custer in Richardson.
...and I'm sure I'm missing _something_ but I'm gonna wrap this one up now. Maybe I'll have a third post with stuff that's fallen through the cracks, maybe not.