I bought a PowerMac G3 (from ebay, about 15 years ago) and while it was not very powerful, the thing was just fun to work with. I ran Linux and had added all kinds of PCI cards like old analog TV tuner card and SATA RAID card to run it as NAS. And the case was very beautiful. I'm not sure how they did it, but Apple and Steve Jobs made plastic look very pleasing to the eyes. Afterward, I also saw someone's PowerMac G4 in person and that thing looked incredibly nice, especially the mirror finish. These macs looked better in real life than in photos. I never got the G4, and I wish I still had that G3.
Beige tower, desktop, or the blue and white tower? I always wanted a B&W G3, my friend('s parents) had one and it was a beautiful machine. I had the desktop "beige G3" and I ran it for a long time. Added a 433MHz G4 accelerator, overclocked the bus/memory, ran some software to allow me to use later versions of OS X, installed a radeon 9100 (I think it was) GPU that I flashed to make it run on mac hardware. It was my main machine in the early 2000s, up until I built a core duo machine to run linux. I have very fond memories of Macs of that era.