How to stop spam submissions?

I can see Spamfighter Pro is a spam filter for home and office PCs or servers. We are talking of the best Captcha or MOD implementation on web directory submission forms to prevent spam/automated submissions. Do you have any idea of the best out there one can use?

 

you can use category selector made on JS

 

If you don't mind cleaning out spam all the time like I do, think of it a hits. But if you want to get rid of it, there are several solutions at the phpld forum site.

 

I am using captcha