Oh, the GIMP is kinda obligatory but you got to have Gnome...
GIMP doesn't require GNOME, but GTK and some related libraries.
Dolphin is so nice, but all those KDE deps for one program?
KDE5 is changing that.
I understand toolkits and DEs and they provide a cheap basis on which to build lots of software... but if you want just one excellent app (K3B, Inkscape, etc.) your machine will get a lot fatter -- not to mention the conflicts which might^H^H^H^H^H will arise.
What conflicts? I usually run KDE with evolution installed (need a mail client with Exchange support), and have never, in mqny years see any conflict. For many years (when actively packaging gui apps and thus needing to test menu entries)
I ran with multiple full desktop environments installed, and saw no conflicts.