My common gripe with multi-functional hardware informational utilities like PC Wizard is that they are sluggish and pain to navigate for quick and often needed lookups.
Open Hardware Monitor (via ghacks) is specialized app to display hardware temperatures, voltages and frequencies.
What it does
App detects and displays information from sensors, embedded in computer hardware. Such as temperatures, voltages, clock and fan speeds.
Strong features
App is compact, starts fast and has extremely neat and efficient presentation of values in interface, nicely coded with small icons.
There is also option to plot any values over time ( View > Plot ) and save report in plain text.
Downsides
Currently in beta and versions come out quite often. I rarely post about early versions, but this one works perfectly for what it does and I got tired of staring at it in buffer folder.
Could totally use indicators in tray, which are staple feature for performance monitors.
Overall
Efficient and straightforward app that is good at both getting and presenting information. Open source, works without installation, requires .NET Framework.
Home http://openhardwaremonitor.org/
Download http://openhardwaremonitor.org/downloads.php