Windows 7
Got my Windows 7 upgrade DVD from the states a few days ago. Why it had to come from the states I'll never understand. The DVD was free but the transport was flipping ridiculous, don't Microsoft know that they have an office in South Africa and it would be cheaper for all concerned to ship some DVDs in one crate to SA and have them distributed locally. They could even have sent the serial code via email and allowed us to download the media kit, while we waited for the package to arrive from overseas.
Well, I did a fresh install and it was super fast. I was a bit frustrated with the fact that Dell didn't send me a copy of the latest drivers. Windows didn't natively support my integrated 3G, so I could not get online as fast as I would have liked to, thank goodness, Windows 7 had native support for Bluetooth and I could hook up my Sony Ericsson in a matter of minutes and downloaded the required drivers from Dell's support site.
I have found Windows 7 to be an absolute pleasure to work with and had all of my programs installed and running in less than a day. I find the performance to be substantially better than that of Vista and it requires far less resources. Will make sure that I have got all the required drivers before I do a fresh install again.
If you have got the option to upgrade or you're buying a new PC, if you're not getting a Mac or going with Linux or Solaris, get yourself Windows 7 and be sure you'll be happier than you were with XP or Vista.