IMHO for the best sushi (price not an issue) is Tojo's on Broadway near the Holiday Inn.
For the best flexibility in all-u-can eat options is Shabusen on Granville (near 14th ave I believe).
For the best quality Sashimi at all-u-can eat and decent quality all around is Richmond Sushi (in the mall behind Crappy Tire on No. 3 Rd, don't remember the side street name). The locals will kill me for releasing this one as it is a popular place.
For reasonable price and high quality, there is another place in Richmond (I think called Haro Sushi) in the same mall where Toh Far Studio used to be. It is a little hidden away corner type set up for really good sushi and a huge selection of sake.
I find that sometimes Kisha Poppo and Tampopo downtown and the Kisha Poppo in Richmond have served me bad sushi that gave me the runs. However, if you are looking for a deal, the Kisha Poppo in Richmond has an after 9:30 (or is it 10pm) 1/2 price special on the all-u-can eat.
For Chinese, all-u-can eat there is the Urban Buffet downtown (I believe on Hornby) which has a large selection of westernized chinese food as well as a good selection of seafood items (the deep fried shrimp and crab are my fav there).
For decent quality Chinese, I like a place in Oakridge mall (I believe it is called Fortune House Seafood Reastaurant), good for Dim Sum too. There is also a place in Richmond in the same mall as Hon's but the entrance is located in the multi-level parkade. This one is so popular you either need a reservation or know the owners to get in fast.
The Pink Pearl on Hastings st. just outside of China town is also a nice staple.
For E. Indian, there is Ashiana's on Kingsway near Knight (fantastic butter chicken and their vindaloo is what got me started on curry, watch it though it can be really spicy)
For all-u-can eat E. Indian I like Zeenaz's which just moved down to Main and SW Marine Drive in the mini-mall across from the street from the superstore. The cuisine is south african E.Indian food so it is different but good none-the-less and they are cleaner than a lot of the other E. Indian buffets. The Himilayan on main and 50th is 2nd best for all-u-can eat.
For Malaysian, Indonesian and Thai, I like Tropika on Cambie and 15th.
And so that there is no ethnic bashing here:
French - La Belle Auberge in Delta
North American fusion Sammy J Peppers (cute chicks too)
N. American all-u-can eat the best is the Country Buffet in Bellis-Fair mall (sorry guys that's one thing the Yanks do better than us and that is eat. Even their mac & cheese is really good).
So there you go, there's my list, lots of places to try.
Enjoy