Note that as other suites gets released, we'll be updating this story. And for those of you who like the wayback machine, here's last year's roundup.
So far this year, we've looked at nine premium suites: Panda Global Protection 2012, ZoneAlarm Extreme Security 2012, Bitdefender Total Security 2012, Kaspersky Internet Security 2012, Trend Micro Titanium Maximum Security 2012, Lavasoft Ad-Aware 9.5 Pro Internet Security, AVG Internet Security 2012, ESET Smart Security 5, and Norton Internet Security 2012. There are still a few more suites to come.
In terms of security, so far the new Bitdefender is the newest suite that will keep you safest. It outperformed last year's leader, Norton Internet Security, blocking more malware and viruses, and detecting fewer false positives, than any suite this year. Determining which suite will keep you safest is an imperfect science, especially because CNET uses multiple third-party sources to ensure that our results aren't skewed by a single test. However, Bitdefender consistently scored at the top or among the top four suites tested, and so we're confident in recommending it above all others if security is your only determination.
In terms of system performance, as you can see on the chart below, Norton Internet Security remains the suite with the lightest impact on your performance. (Read more on how CNET Labs tests security programs.) However, this year it under-performed on two key metrics: boot time impact, which is the time you have to wait to use your computer after turning it on; and scan time, the amount of time it takes to run a scan. Bitdefender's impact on start up and shut down times leave much to be desired, but its affect on your computer as you use it turned out to be minimal.
It's also $10 more than Norton Internet Security, so we strongly advise you check out the free 30-day trials and be sure you're comfortable with the price you'd be paying for the protection and ancillary features you'd be getting.
Overall, we're comfortable at this point with recommending Bitdefender as the best high-end security suite so far this year. That may change as the last few suites get released, but
How the Fall 2011 security suites impacted system performance

Security Program	Boot time	Shutdown time	Scan time	MS Office performance	iTunes decoding	Media multitasking	Cinebench
Unprotected system	40	6	n/a	395	120	342	17,711
Average of all tested systems (to date)	63.0	15.8	1,136	416	125	348	17,112
Panda Global Protection 2012	46.8	22.3	1,191	432	126	373	16,912
ZoneAlarm Extreme Security 2012	66.5	17.4	1,825	423	125	348	17,310
Bitdefender Total Security 2012	61.6	31	920	402	127	346	17,363
Kaspersky Internet Security 2012	61.3	18	1,320	429	125	345	17,122
Trend Micro Titanium Maximum Security 2012	88	11.3	502	437	125	345	17,290
Lavasoft Ad-Aware 9.5 Pro Internet Security	54.4	16.9	2,080	405	125	347	16,884
AVG Internet Security 2012	69.9	11.3	792	416	124	344	17,259
ESET Smart Security 5	57.2	14	658	401	124	343	17,148
Norton Internet Security 2012	51.8	10.3	1,066	410	123	343	17,386

*All tests measured in seconds, except for Cinebench. On the Cinebench test, the higher number is better. Times in bold are the best in that category. Tested on Windows 7 64-bit Service Pack 1.