As far as reputations go, ESET's NOD32 is practically unimpeachable. Version 4 of the popular and effective antivirus and antispyware builds on that rep, emphasizing its community-sourced ThreatSense for preventing attacks before they occur, a slick interface, and some of the highest independently-tested detection rates married to low rates of false positives.
Installation is clean and straightforward. Greatly improved from its humble beginnings as separate scanners that once littered the desktop, NOD32 can be toggled between standard features and more advanced options. Scans were neither blazingly fast nor excruciatingly slow, but the real-time defenses produced no noticeable drags on system performance. NOD32 has consistently scored near the top of several independent antivirus testing organization ratings for finding the most malware. An uninstallation option is available, requiring a reboot. However, we found residual system files and Registry settings that had to be deleted by hand.
If you're confident in your clicking habits, you might not necessarily miss the firewall and spam filter that ESET built into its Smart Security suite that's based on NOD32. Even without them, though, NOD32's speed, accuracy, and lack of impact on resources make it a must.