SuperAntiSpyware Has both free and paid version. Its quite good tool.
Malwarebytes anti-malware falls in the same category, you can try it
out too (free version available).

There are too many parasites, and one tool might miss some, even for a
while. Some security experts suggest using more than one remover for
making sure.
Also, you can easily fall for spyware scams (rogue products) which
claim that they found spyware you have not. So better visit some
review sites to determine whats good, whats not.
Pros for paid products :

1. You are entitled for something - support, money back, or maybe even
security expert if software fails. This rarely is done by "free" tool
companies.
2. Big companies have resources to include more parasites and faster
than free scanner manufactures
3. Reputable/paid remover manufacturers have responsibility for their
database - they cant risk to remove good programs or screw your PC up,
or they will get sued and go out of business quite fast. Most scams
are short lived.
4. More features.

Cons for paid products
1. Pricing - noone likes to pay for what you can get for "free"
2. There is less risk to be pushed a product that is bad if they do
not depend on you paying it or not.

I would go with free remover of your choice if there is no problems at
the moment. When you get infection and free products does not help, i
would consult product reviews sites for good paid product or for
specific free solution for parasite you got.