Favorite diagnostic tools

Hey all. Back in my day (4 months ago) I was a technician at CompUSA. Here is a list of good utilities that are free that should help you diagnose any PC troubles you may have.
Ultimate Boot CD
The best of the best, UBCD does almost every test known to mankind. A small bootable ISO image that can be burned to a disc, it has utilities that can resize partitions, recover data, check a drive for defects, run anti virus scans, check memory, etc.
Here is a quick rundown of what ones I have found effective.
The best hard drive test that I have found is MHDD. It not only checks for bad sectors but also for any timing issues that the drive might have. If your drive is getting above 150ms, you should look at replacing it. Consider 500ms to be a dead drive.
For memory test, memtest86+ is the king of the hill. On most machines one pass is effective, but if you are experiencing issues and there is no faulty hardware and you have already reformatted, let memtest run looping for 2 or 3 days.
If anyone needs any computer help, feel free to ask.
Sincerely,
Phreakuency