ECU upgrades?

i'm thinking of upgrading my ECU with a chip or module... just curious as to what the best way to go is, and if there's any good gains to be had out of all the "bargin" ebay chips and modules. the more work i do, the more i realize price really does make a difference.... anything that cheap leaves me a bit weary.

Depends on your car...there are alot of "chipped" JDM ECU's floating around on Ebay and there are many people out there than can always burn a custom chip for your specific application.