For me its really hard to say. Maybe its because it took me SOO long to finally own a Mac - personal hardships and excuses asside.
Pismo (Powerbook G3) was awesome and featured in so many movies you couldn't ignore it if you tried. Come to think of it, I cannot think of more than 1 PC laptop that came close to its performance.
A friend of mine teased me with the PowerMac G4 733Mhz QuickSilver for 3 mths on loan. Man Cheetah & Puma (I upgraded it) where horrible yet so inviting that it was just beautiful. Free classes to learn the basics at CPUsed on Dupont helped. I was a great machine - best with Dual 1Ghz G4; and gets a worthy mention. This was what the G4 should've launched with.
But its THIS machine that just did it for me. Like the first girl at high school that I had a crush, no, obsession with. I walked to the nearest Apple retailer (both Apple & Palm/Psion retailer), and this machine had a lineup for people just to touch it, see it in action. THIS machine made OS X a real dream to enjoy, crushing the long time favorite the Pismo; it's only achilles heel to massive appeal was the price, and case pealing. I vowed I would own one, and I finally bought one last month. I'm happy with it, considering its age.
Next up will be a MB 13" Unibody and hopefuly a Mac Pro 8Core late 2008; I got 2 sweet 17" & 20" Dell LCD's just waiting for them.