Avast is a Good Residential Scanner, but what is the best to do a second scan?

Viruses and worms
1

I have Avast, but I see on the forums, many things such as MalwareBytes, and Super Anti Spyware, and Spybot Search and Destroy.

If there is anything that is really important or good to have please make a comment.

Even its not from above.

I don’t know which is legit either.

2

All the ones you’ve mentioned are legit.
avast is not perfect (any software is…), so having a second opinion is useful.
MalwareBytes and SuperAntiSpyware are among the best ones to run only on-demand (not resident).

3

Do you think it is okay to have all those at once?
Or should I just choose one.

4

You can have the three. If you want to choose just one, MBAM will be my choice.

5

For a malware scan I use SAS and/or MBAM.

For a good thorough virus scanner “second opinion” DrWeb CureIt may be the best. Also free.