Q: what is the best antivirus for my mac?

None. There is no need for additional antivirus software. Most commercial antivirus software is junk and some of it is harmful.

None. You really, really don't need any.

MacKeeper is better known as malware. Do not go anywhere near it.

Uninstalling MacKeeper is not trivial.

It is bad. Do install it. All it will do for you is cause your Mac to have problems.

I prefer to call it scamware especially after the way Zeobit advertises it.

Allan

MacKeeper is a really nasty "anti-virus" program. I have never run it myself, knowing it's bad, but this thread should answer your question:

https://discussions.apple.com/thread/3057579?start=0&tstart=0

As others have said, stay away from Mac keeper.

So far, there has really been no need for Mac anti-malware products. However,  I don't want to be stuck wondering what happened if a serious Mac threat comes out.

http://www.clamxav.com/ is worth considering. It could be that OS X continues to not be a focus of malware attacks, and I am not suggesting that there is impending doom. I guess I just don't want to be caught totally unprepared *IF* there is a sudden malware attack aimed at OS X.

No problem

Some suggestions for you: In Safari Preferences, uncheck "open 'safe' files after downloading".

I believe it is checked by default. Un-check it. This gives you a measure of protection against apps that automatically open after downloading. Malware exists but you have to install it, and you have to supply an Administrator name and password to do that. Nothing can save you if you come across a dubious website offering "iLife 11 full install!!!" and you install it with your name and password. You'll get what you deserve.

Become knowledgable about phishing. Mac OS X has built-in warnings about phishing sites but there is nothing to stop someone from asking personal information. Phishing a modern version of a confidence game that's been around for thousands of years. Nothing can stop it except your own common sense.

Ignore pop-ups that offer to sweep your system for viruses, or that it has already been infected by whatever. These are phishing attempts or offers of malware. Select "block pop-up windows" in Safari's menu.

Download and install ClickToFlash. This intercepts Flash content before it can bog down your system. Flash isn't intended to be malware, but it can act that way.

Run Software Update periodically. This will ensure your system has the latest security updates.

Read more: http://www.apple.com/macosx/what-is/security.html

For a thoughtful, balanced discussion of the few malware threats that do exist on the Mac and how to avoid them, read:

http://www.reedcorner.net/guides/macvirus/

I'm sorry John and stevejobs fan, this is terrible advice.  The idea that Mac OS X (or that -any- operating system for that matter) is invulnerable is flat-out wrong.  Mac OS X / FreeBSD's security model does not prevent trojan horses, or security flaws, although it may be more secure than Windows in some situations.  In other circumstances, it's -less- secure.

I suggest you guys look at:

http://www.forbes.com/sites/rogerkay/2012/04/09/flashback-champions-refight-mac- vs-pc-battle-on-security-turf/2/

...and then checkout

http://arstechnica.com/apple/2012/05/hands-on-with-five-antivirus-apps-for-the-m ac/

I personally run Intego, which generally is fast and has a fair number of add on features...but I'm considering switching to Kapersky.

No one claimed Macs were invulnerable. The statement still stands that no anti-virus software should be installed. The miniscule amount of malware out there is usually not caught by AV software, or will be caught by OS X's built in protection. Apple came out with a patch for Flashback very shortly after it hit the news.

The best defense agains virus for your MB Pro is OS X Lion.

If however, you want peace of mind, download ClamX AV and do a scan once a week if it would make you feel better.

Another way for you not to get any malware or trojans of any kind is to follow the safe browsing rules.

Other than that, enjoy the fact that you're using a MBPro and not a windows notebook.