It might be time to think about un-sticky'ing this thread since Picassa has been gone for over three years now...

My "Go To" image-editor for simple things is IrfanView (irfanview.com/).
It loads almost instantly and has all the basic tools.

For other stuff I can't be of much help, Adobe got me hooked on LR many years ago and I just can't seem to kick the habit...