best antivirus for corporates

I have worked with symantec, trend, sophos and Norton.. sophos seems to be the strongest antivirus I have used and is relatively simple to implement and maintain.

http://anti-virus-software-review.toptenreviews.com/small-business-antivirus/

How big is your corporate environment?
How many sites do you have at different location?
Approximate number of PC, Laptops and Servers?
Do you have any legacy server OS like Windows 2000?
Do you require AV for Linux/Unix/MAC OS as well?
Is there any team which manages and would support this task?
Do you require other features like NAC, Antispyware, Firewall, IDS/IPS, Device Control along with AV on User's system?

Answer these question before you came to any conclusion.

In my experience there is none better than McAfee for actual protection. They also have the largest market share and research division and are very proactive with finding new threat definitions. A recent announcement informed the public of the ability of their upcoming release to insert a layer of protection between the hardware and OS for the ultimate safety.

See http://www.mcafee.com for more information.

This is like asking what the best flavor ice cream is.  EVERYONE has opinions.

I'm no different.

Symantec/Norton is HORRIBLE.  AVOID.  Causes problems WAY too often in my experience.  At least google is honest in saying their products are in beta... if you look at the quality of Symantec products, they've been selling things even though they are only beta quality.

ESet - light weight but at the one client I had it installed at, somewhat ineffective.

AVG (paid) - went to a new client (private school) - when we replaced it, the replacement software (below) detected several things AVG missed.

McAfee - BLOATED and somewhat ineffective (it was a long time favorite of mine, but fell out of favor about 4-5 years ago as I found it getting ineffective and still a resource hog).  Also expensive.  Only win over Symantec products - it doesn't cause problems

Kaspersky - seemed ok - only had it at one client... but it was a HUGE PITA to update the version when a new one came out... and their support was a nightmare.

Avira - had a client with it and it blocked their internet access with a bad update... in fairness, everyone can have a bad update.

Trend - never used it but had a client that did... I love it - it causes so many problems I made so much money off it!  I did promptly recommend they switch to VIPRE... it's especially a problem on servers when adding new services as it blocks various services and masks the reason why things aren't working by poping up Windows error messages rather than a helpful "Trend has prevented this from working..."

MY PREFERENCE: Vipre from GFI.  Cheap, lightweight, and in my experience, it works.  Tech support is also VERY good.  I have a large corporate client stuck using Symantec getting infected once per month or so... all my other clients (3x the number of users as this large client's office I help with) run VIPRE... I can't remember the last infection I had to clean...VIPRE has replaced ALL the above products - AVG, McAfee, Symantec in one case, Trend.

I don't care what Gartner or anyone else says... these are MY experiences... and there are probably 4 or 5 DOZEN other products you can try... Pick a few, test them, cross fingers, and move on.  Sorry... wish I could be more definitive but these are my experiences and recommendation based on them.

We use Trend Micro here, about 500 PC's in the enviroment.  Causes us very few problems, and has an email function as well to notify us IT admins when a threat has been detected.

I wholeheartedly agree with leew on almost all of what he said in the post above.  My experience with a slew of different solutions, both managed and unmanaged, left me wih one conclusion GFI's Vipre for Business was the best overall.  

ESET has the best console if you are doing managed, but the endpoint solution (Smart Security) puts hooks into your operating system that are difficult at best  to get out. ESET's NOD32 is an excellent product, but you need to have an external firewall surrounding the machines running it or it doesn't pass muster.

I really think if you want to do any sort of central management of the AV clients ESET is the best. I find it to be rather effective at stopping most threats and it proves to be quite resillient against most attacks.

ESET is definitely the best console, as I said, but GFI's console is second best.  ESET is definitely effective, but when I went to uninstall it, I completely lost my network.  The ESET support people (who were great BTW) did everything they could, but I ended up having to go back to a restore point before ESET was installed.

AVG paid is what I have had the most luck with.  Eset is good but last time I looked into it they did not offer an Exchange component.  Kaspersky/Symantec/McAfee/Norton are all horrible, high maintenance, terrible support and a general PITA

I might add that this has just become a sore point here at my work.  Although in my department I administer Vipre and deploy it, the university has invested in SEPM.  Now we are trying to come up with not only the best alternative, but also one that addresses the cost issue (I keep telling them that in reality the cost is NOT getting good protection).  

In light of that and the fact that we already have a Microsoft CAL and are using Exchange 2010 and Forefront Online Protection for Exchange, does anybody know of the benefits of Forefront?  Does it have a console?  What is the site license fee?  Does it only work on windows boxes?