For me it's ESET Internet Security. It's lightweight, unobstrusive and has no impact on the performance on my PC. Not to mention the detection rates that is Superb. I just wish it had a rollback feature and application control like Kaspersky.
long time ago i liked Emsisoft whenes come with online armor with avira..
Now i stay with custom build casue most Internet secuity have 1-2 layer module good rest are bad.. or even lack of it (Good firewall and bad AV or good av and not good at all firewall)
SecureAplus: as great multi-scanner casue improve detection ratio more database more change to detec infection
SpyShelterFW: Excelet advenced HIPS with anti-logger features which you can't find in rest similar software
Shadow Defender: & Sandboxie: do i rly have explain it why i use it ?!
K9 Web + Adguard / umatrix this is pure high web protection.
More detail you can find in my pc config
System still work fast and smooth, old video but nothing much changed since few weeks
Eset has always worked great on my system.
It's performance it's always very good.
Only Webroot can match it's performance on my system.
But lately i have begun testing default deny solutions to protect my system.