Best Affiliate Script?

[wordplay]

Hi All,

From my site LogoDiner.com, I'm going to be offering my
customers a free t-shirt imprinted with every logo design ordered.

I'll be offering web site owners $3 OR a
free t-shirt with their existing website logo imprinted on it,
per refered order.

Could anyone recommend a good affiliate script?

Thank you.

 

[rb]

I like groundbreak software's Ultimate Affiliate software.

A lot of companies use it and being on the affiliate side of it, it has great features.