One of Hong Kong's unique delicacies is roast goose, specifically served with a kind of rice noodle called "lai fun" that you can't seem to find anywhere else in the world. The most famous place in town for roast goose noodles is Yung Kee, a multi-story establishment in the Central area of HK. On my last trip to HK, there was some kind of temporary regulation against goose at the time, so I was denied this delicious experience. Not so this time around, and my dad promptly made a trip during a terribly hot day (actually, pretty much every day was terribly hot) for lunch. 
roast pork Although Yung Kee is famous for its goose, it's actually a full-fledged Cantonese restaurant with a complete menu to match. So they've got all different kinds of meats and dishes and what not. We got a plate of char siu to share, and it was pretty tasty, though we later found out we could have specified for fatter cuts of pork. Still, the meat was tender and flavorful. Next time we'll get the fat ones; I'm sure that tastes even better. 
roast goose leg And there it is, in all its glory. To the naked eye it looks pretty much like duck, and it is actually quite similar. But the flavor is just a bit different - goose has its own distinct taste, and to me a good roast goose is like a better version of roast duck. Also, the skin isn't quite the same, with a slightly different crispy/fatty balance. Goose is definitely something you have to try if you go to HK. 
lai fun You can order the goose on top of noodles in a single serving, but we just decided to get the 2 meats to share and each get our own bowl of noodles. These are the famous lai fun, which is made of rice and looks a bit like a translucent spaghetti. It has a very light, bouncy texture and goes extremely well with the goose. It's hard to find lai fun outside of HK, and usually when you do it will be solid white all the way through like a typical flat rice noodle, with a taste and texture to match. I guess it's because of some combination of lai fun being really hard to make, really perishable, and not particularly profitable.
I didn't take down the exact prices but the meal cost something like HK$100-120 a head, which is about US$15. If you just get a roast goose noodle soup, you can probably get out for US$10. We just barely missed the lunch rush; the place gets really crowded, and if we'd gotten there even 5-10 minutes later than we did, we would have had to wait in line. Definitely worth checking out if you make it out to Hong Kong.