I'll be honest when I say that I'm totally biased when it comes to Wan Fu. I love their hot and sour soup, and in my book, that's all it takes to be great in the Chinese restaurant business.
They have a great menu full of choices, which can be overpowering if you have no idea what you're in the mood for. If you're looking to dine on the cheap, skip towards the back of the menu and order off their "dinner combos" which come with soup, egg roll, white or fried rice and their main dish. For about $7, you'll be taking food home AND be stuffed.
Their beef (or chicken) broccoli is one my favorites anywhere in Austin. They also have a killer Garlic Chicken and Kung Pao Beef.
Another plus is that they close in the middle of the night (last time I checked it was 3 AM), so it doesn't matter what time of day or night you want to get your Wan Fu, because it'll most likely be open.