KDE4 has not ceased to piss me off, so I'm trying GNOME again. So far I like it! I hate the color scheme out of the box, and there are a couple weird little interface things I don't like about it, but up to this point it's actually a lot faster than KDE and -- and THIS is where it gets weird -- much easier to customize.
Not 100% I'll stick with it, but at this point I think it's fair for me to recommend regular Ubuntu to newbies over Kubuntu.
EDIT: The first truly, unbelievably asinine thing I have run across in GNOME is that you can't map Ctrl-Tab in gnome-terminal.
Fortunately, there's no shortage of terminal programs in X, but it's still really frigging stupid.
EDIT 2: You can't even SET keybindings in gedit. The default text editor.
Also, GNOME's "Are you you sure you want to overwrite this file?" is FAR less useful than KDE's. KDE's gives you the datestamps of both files, and the option to rename the new file, not just replace/skip.
I'm starting to think that GNOME is a better desktop but KDE has a better suite of programs.
EDIT 3: GNOME's default not-quite-like-a-Mac top panel is a waste of space, especially on a widescreen monitor. You've got three menus on the left, then quicklaunch, then a shit-ton of empty space, and then the system tray on the right. (Suppose it's nitpicking a bit, but if you minimize a program to the system tray, you shouldn't show a DOWNWARD animation if the system tray is at the TOP of the screen.)
It's similar to how Apple puts the menu and tray at the top and the dock at the bottom, but the key difference is that, while the various MacOS's put the program's menu bar on the same line as the Apple menu and the tray, GNOME doesn't by default. So you get a top panel with a bunch of negative space AND each program gets a menubar with a bunch of negative space. (You can set the panel to autohide, but, while this is fine with the bottom panel, it's a pain in the ass with the top one as you'll unhide it every time you try to click the minimize/maximize/close buttons.)
There are themes you can get to make it behave more like OSX (or Windows), but I don't much want to look through that crap right now, and anyway I'm just talking about something that I think is poorly-designed in the default config.
(I'm also not sure how well the themes work across different toolkits -- a theme that puts a GTK+ program's menubar across the top of the screen might not work for a Qt program or an XUL one.)