People rave about the steamed meat dumplings at Seifuro. For 540 yen, you get served 4 of them, piping hot. What makes them so delicious is their juicy meaty filling that has just the right balance of sweetness and saltiness. As a condiment, there is soy sauce and karashi mustard you can add to them. Ask for vinegar too and the server will bring some to your table. Vinegar goes very well with meat dumplings. Also, try the stir-fried rice with green onions, roasted pork and shrimps if you have a bigger appetite!
For something fancier, you should most definitely try Manchinro. It's a huge restaurant on three floors with a tasteful traditional Chinese decor. Choices abound here. It might be better to take a course meal, although they are a bit pricey (from 6,000 yen for dinner and 2,800 for lunch) you'll be treated to a feast you'll remember! Dim sums filled with succulent meat and fresh seafood, spring rolls and much more! This is one of the most praised restaurants in Chinatown according to many online sources.
Santon is a superb restaurant where you get the best bang for your buck! You can have a sublime meal for about 2,000 yen. The restaurant has won a TripAdvisor certificate of excellence for 2015. Their claim to fame is their home-made "suigyoza" (boiled dumplings). There are 4 course menus available from 2,160. They also have an all-you-can-drink option for 2 hours for 2,160 yen.
Another great dim sum restaurant is Saiko Shinkan. First, you'll be struck by the gorgeous interior of the place! The restaurant is huge and has a refined Chinese style. The dim sums here are hand-made using fresh ingredients and there is a lot of variety! Must-try items here include the deep-fried shrimp wafers, the sesame dango balls. Course menus are available. Get the 9 type of dim sum course for 3,000 yen and you can't go wrong.
Shofukumon is another place where you can have a memorable dim sum experience! Every dumpling here is hand-made under the supervision of a chef from Hong Kong. They have some special dumplings varieties such a the green spinach gyoza. The interior decor is refined and warm. It's the ideal place for enjoying a dim sum feast with a small group. There is an all-you-can-eat option with no time limit for 2,800 yen which includes 50 different types of dim sums!
Also, check out this article for other great restaurant suggestions in Yokohama's Chinatown.