UAC is one more line of defense against hackers and malicious software. With all the recent talk about Java exploits, problems involving Adobe and Foxit Readers, etc I'm not at all upset about having to click on a "yes" button that UAC might throw at me. I'd rather "waste" a few seconds every hour to click the UAC prompt than to spend a whole lot more time reinstalling everything because some malware got through. But to each his own. 
User Account Control - Microsoft Windows

User Account Control - Microsoft Windows
My Computer
At a glance
Win 7 Pro 64-bitIntel i5 2.4 Ghz8GB DDR3Intel HD 3000
- Computer type
- Laptop
- Computer Manufacturer/Model Number
- Sony Vaio VPCEB47GM Laptop
- OS
- Win 7 Pro 64-bit
- CPU
- Intel i5 2.4 Ghz
- Memory
- 8GB DDR3
- Graphics Card(s)
- Intel HD 3000
- Sound Card
- IDT High Definition
- Monitor(s) Displays
- 15.6 WGXA Anti-Glare LED
- Screen Resolution
- 1280x800
- Hard Drives
- 640Gb 7200rpm
- Antivirus
- MSE
- Browser
- Opera (primary) with IE9 backup