I've had 3 so far, 4 if I count my wife's nano.
My 1st was a 3G 40GB Classic-2003
My 2nd was a 4G 60 GB Photo-2005
My 3rd and current is an 80GB 5G Color-2007
I am pretty happy with the one I have, and haven't really felt the need to upgrade again, I will eventually but not soon. I currently have 10,248 songs on it, space would be the only reason I would feel the need to upgrade, but I have everything I want on there so I'm good.