Does Ubuntu need an Antivirus? If so, could you recommend a good one? I am interested on the Ubuntu side only.
I asked myself the same question a bit ago and when I asked it, I was told that no Ubuntu did not need an antivirus. Mainly due to the fact that the people creating the viruses were going for the big markets (e.g windows) to get the most impact. However, as more and more people come to the Linux side, this may change. If it has not already.
I did use ClamAV Antivirus, but now I do not use one and I have not had an issue.
This site may give you a bit more of an insight Antivirus for Ubuntu
I would agree with Phil UK's comments - but ask yourself the question what am I trying to protect ? What is it's value - either to me - or to my company/employers/staff or customers.
If it is your home pc and you only use for Steam gaming - the "cost" is probably 0 - assuming your CC Details for your Steam account are not on that machine. If it is work related... Why not go ahead and protect your machine....
You probably want to look at a firewall and some basic log checking and IDS at the same time.