I use a dual 1.8GHz PowerMac G5 at work. I have an identical system at work that I use for testing stuff on. At home I have an old G3 that I use for, well, nothing really just for kicks. Besides that I have a Macbook Air, Macbook Pro, and 2009 Mac Mini. The PPC stuff runs quite fine, but the Intel stuff runs better
I have a G4 cube that I use occasionally but as time goes on, I find it more difficult to have it sit there and eat up desk space. I'm tempted to sell it or put it away in my closet.
I loved the cube design and it was my first "power mac" (had an iMac an SE before that) but now its more of a dust collector
I still use my 17" PB G4 on a regular basis, though I have to say the C2D Mini has taken over as the main machine. The PB is the living room computer. I use it when I get bored or have an ADD attack while watching TV.
Even though I have a Pro now, my wife and kids use a networked iMac G5, and next to my Pro is my iMac G4 where I use all my legacy programs from before OS X.
PowerMac Dual 2.5 G5 web server in my lab.
iBook G4 1.14 in the lab for students to use.
Kids each have iMac G4 1.0
uMBP Intel as my portable computer.