I love my 17" 1Ghz iMac G4 and I'm hoping to keep it forever. I may even upgrade it to a 1.92Ghz G4.
But...I would trade it for a 20" iMac G4 or maybe even a 20" iMac G5. I'm not crazy about the new iMac's design but I'd love to have a 20" LCD for video editing. And as some else said, the G5 would be nice too.
Power Macs don't interest me at all right now and I don't need portability. IMHO, the iMac G4 and the G4 Cube were the most beautiful computers ever and I'm lucky enough to own each of them.