Cool Edit 2000 (the lower cost version of CE Pro) and the Noise reduction plugin..
If I remember, base CE 2000 costs $80 USD, and the various add ons are $50.
You get various tape hiss, noise reduction, auto pop and crackle removing and
some fancy filtering with the one add on you want.
CE Pro has ALL the plugin features, and more, and costs $250. www.syntrillium.com
The auto noise remover is pretty well thought of at Clive's LP to CD Tips site:
http://www.delback.co.uk/lp-cdr.htm and I've had good results with it. He reviews
several programs there and covers their pro's and cons..
This site is a must read for those interested in processing their LP's. I also use
his own piece of software, Wave Repair, for getting down and dirty with manual
editing, though it has an auto remover as well... Recommended, it has many features
designed only for this particular purpose and only costs $30