Disclaimer: I have done Eve, Duna and Laythe in the past.
Honestly though, in most games I spend 95% of the time on Kerbin. I entirely blame Firespitter. Propeller planes, helicopters, propeller rovers...
Then I found Hooligan and it was blimpcars, baloonplanes, etc. Add in Extra-planetary Launchpads and there was the month spent using blimps to build a 'second KSC' up in the mountains. Only to find Kolonisation and start building another one over in another mountain range. All culminating with a city-plate-colony airlifted to the South Pole.
Now with the GAP contracts...
..space? Meh. Maybe when I'm between coast guard rescues and submarine explorations :P