I'd say powerful lappy. mine I do almost everything with it. photoshop, surf, skype or call with my girl( which is obviously I cant have with the desktop. that would be the main reason I love my G6.) and love desktop for the larger screen for play games and work. but yet I just plug my notebook to 42" LED tv for watching movies and using that and if I thought to have a loud sound with gaming on notebook, I hook up to both TV and 7.1 surround system which gives me rumbling sound while firing heavy arms in crysis
but yet desktops are powerful. but if you have a notebook that can do everything you want, you'll love it. and of course I cant bring my desktop to my bed
and this may off the topic, but more than my desktop and lappy, I love my galaxy SII which I cant live a day without it.
I think you should add smartphone too, cuz I think young ones like me prefer our phone more than desktop and laptop.