There are quite a few of both good ones and ripoffs. Bob Proffit's list here has quite a few of the good ones.
This web site here will tell you some of the ripoffs along with a reason why.
Hope this helps.
Out of all the spyware removers being offered lately, what ones do you find the most effective and which do you consider a rip-off? Is it really necessary to pay for one, are they that much more effective if you spend the money on their service?