The first one i came across is VIPRE from Sunbelt software. It uses a spyware+antivirus engine that makes a combined effect to keep your operating system clean. It's Advantages are:
- High-performance threat protection with low impact on system resources
- Scans email for malware threats
- Cutting-edge Proactive Protection guards you 24/7
- Advanced anti-rootkit technologies
- Small, regular definition updates greatly reduce update downloading time
- VIPRE has three extra bonus tools: a history cleaner, a secure file eraser, and the PC Explorer for advanced users.