A decent chip is the Xecuter 2 Lite, which runs around 30 dollars or less. Or the Aladdin chip, which is like half the price I think. But whatever, don't ever get the Spider chip. A load of people have troubles with it. If you can, get the Xecuter 3 CE chip or the Xenium ICE, they both offer more features than the former chips that you can take advantage of. There are others like the SmartXX and the X-Chip. But these are not as popular as the Xecuter 3 or Xenium ICE, so you might not get as much support if you run into problems with them.
I agree with Achilles3, get either the X3 or Xenium Sp.ICE. More people will be able to help you out if you have problems with the X3, seeing that is the most popular chip people buy. Not saying the Xenium isn't as good, just saying the support is better for the X3