i think i have asked that often already, but will do so again: if linux with its various desktop environments looks bad, ok.... but what then looks good in your eyes? windows? oh please.... how old is their aero style now? 7 or 8 years, nevermind some icons are still from windows 95 times....
macos x? yep maybe they have put most time in a good style but current kde offers way more options and tweaks.
i put it that way: no virtual desktops or not having the option to shade/roll up any window in 2014 is quite sad and absolutely not anything of a good desktop.
kde's dolphin for sure is >>>>>> macos finder >> windows explorer
and for the rest: i can move all window buttons to the left/right and can add / remove many of them the way i want. most linux are shipped with MUCH more styles and themes than windows or macos. and online you can find even more.
i also dont like the dark ubuntu theme, i am not keen on unity and while i find gnome 3 interesting, its lacking some options for me.
but at least i can chose. if i could build a linux distro i would make one where you have gnome 2, 3, kde and maybe xfce installed and add a little nice hint and a screen after frist boot where its explained that you can chose another desktop everytime before login.
thats so much more the other os have to offer, and its for free. and given some tweaks, the desktop can look impressive. for me even a default lxde desktop looks better than the boring win 8. i had those tiles as a part of active desktop in win 98 already and even by then i did not like it.
but even then, if you like you can make linux look like win xp or win 7 easily, also like macos. try to customize win or mac the way. either you will need to pay loads of money for some tools i can have free in linux, or you run out of ideas/time.