I don't think you will find much solutions are available anyway
Which means most likely if you come accross a website that tries to sell you an antivirus solution for Mac unless it's a big name like McAfee or aVast (check the url), it's going to be a scam trying to get you to install something.
False sense of security but still fewer threats than Windows
Dont be fool by false sense of security , all PC or Mac has weak codes, if man made , man can break. But still less chance to get than Windows base pc... you have many choices, free Sophos, Avast, so on.... Be better safe than do nothing... good luck
Lots of people don't. I never use virus/malware protection. I used my current PC laptop for 3 yrs, finally installed AVG, ran a scan, nothing. For me, it's common sense and being wary of certain stuff on the internet that protects me.
On the other hand, lots of people don't have as keen of a sense as others as far as internet/computer safety is concerned. I think that anyone who needs to ask whether or not they need it does in fact need it. I'd err on the side of caution if I were you.
Like others have said, you really don't need antivirus software on a Mac. If you want extra piece of mind; however, you can download free programs from the App Store such as Virus Barrier Express or Bitdefender Virus Scanner. Sophos Antivirus is also a decent program which scans for both Windows and OS X viruses, which may or may not be relevant to you if you're working with Windows PCs or Bootcamp since Windows viruses that are harmless to OS X may be transferred to them. I find that those apps aren't obtrusive or hard to deal with like many other antivirus apps or even trial versions of those premium products like Intego or Norton Antivirus, which really are a waste of your money. In all seriousness, you may not even have a use for the free apps either because 99.99% of the time all you're gonna be doing is running a scan to see the 'No viruses found' indicator. It's a shame too, 'cuz I always wanted to click on the 'Kill Virus' button.
Common sense will also go a long way, but if you know you're attracted to risky areas of the web like porn and illegal movie streaming sites then you might enjoy the extra piece of mind.
On a side note, you may want to see if your Firewall is enabled via the Security & Privacy tab in your System Preferences on the iMac. You can also turn on Filevault in the same tab to encrypt your hard drive for added security. If you're planning to partition your HDD with Bootcamp or Disk Utility; however, you might want to enable Filevault afterwards as it can present some complications when you're doing that.
But the best security measure you can take to protect your files is to set up a Time Machine backup with an external hard drive. I've already relied on my backup several times and that didn't even have anything to do with malware. Also, if you're running a Windows partition on your Mac you will want to install antivirus software for it since it will be susceptible to the same viruses as any Windows PC.
I don't believe there are any viruses for iOS, nor are there really any antivirus apps for it. You can download Lookout Mobile Security or Find my iPhone to help locate a lost or stolen device though. You should also be able to scan your iPad for viruses with some of the antivirus programs mentioned above by connecting it to your PC. The only purpose this might serve though is to ensure that your iPad can't unwittingly transfer any viruses which can infect your PC when connected, if that's even possible.
Answer depends on what you use your computer for.
If you surf, various sites, forums,blogs you might be well advised to seek anti-virus protection. On the other hand using good judgement on these sites and not opening questionable emails and Links should be adequate.
In all seriousness, just get ClamXAV. It's an on-demand scanner (meaning it only checks for viruses if you start a scan yourself), and it doesn't have a particularly high detection rate, but malware isn't enough of an issue at this point to warrant having a constant malware scanner, bogging down your Mac's speed in the process.