Believe it or not, I have found sushi to be one of the best poker foods to serve. Also, some of the dim-sum chinese varieties are extremely popular.
The reason sushi works so well is that
1) it is finger food
2) it is non-greasy and non messy, you eat it in one bite
3) the fiery hot wasabi pumps people up and is always a fun point of discussion
4) it can be made for a fraction of the cost of purchasing.
I have also served dim sum, which includes dumplings, wantans, and eggrolls, however, these usually take more prep work and time.
If you host alot of poker games, it might be worth it to buy a deep fryer at Target or Walmart. You can buy packaged of deep-fry foods, such as chicken wings, mozarella sticks, mushrooms, onion rings, french fries, etc.
Keep 'em in the freezer, and when they ask for snacks, heat up the fryer and drop em in.
dim-sum is very popular. You usually can buy bag fulls of pork filled buns, egg rolls, spring rolls, vietnamese rice rolls, dumplings, won tons at an asian store for very cheap. They are either served deep fried or boiled. They are, for the most part, a finger food and people just love asian food nowadays.
For a real shocking opener, try serving 1000 year old eggs. They are preserved duck eggs and sell at the China store for like $4. They aren't 1000 years old, although when you walk into the Chinese food store, you will smell things that smell as if they are 1000 years old.
www.foodnetwork.com has some party ideas, and directions for rolling your own sushi. Stick to cooked items and California rolls, as most people wont eat anything raw.
You'll be surprised how far a package of sea-weed wrappers, a bag of rice, and a bottle of vinegar go. You can make like 100 pieces for under $20. Buy canned sea food, like salmon, tuna, or crab meat, mix it with mayonaise and serve it aka California roll.
just some thoughts
-J