Last year I installed Cyanogenmod-6 because I wanted Froyo on my T-Mobile Sapphire MyTouch. It seemed unlikely that T-Mobile would release Froyo for the MyTouch so rooted the phone. Initially, Cyanogenmod ran reasonably well, but performance degraded over time.
In the mean time, T-Mobile did release a Froyo OTA (Over The Air) update. Of course, having a rooted phone meant that I did not receive the OTA update. My phone was close to unusable, and the reviews for the T-Mobile Froyo update were positive so I was willing to give it a try.
Follow these directions to restore your T-Mobile MyTouch (v1.0) to a stock Android Donut 1.6 DMD64 install, then upgrade it to the T-Mobile Froyo update. Note that the link in the article for the actual Froyo update is broken. You can download the Froyo update from this link.
Happily, I can now play Angry Birds with the rest of you.