After bashing Unity awhile ago, I gave a quick try to some of the other Linux desktop environments in hopes of finding the best replacement for it. These were my first impressions (coming from someone who is not a heavy Linux-user, and most definitely not a Linux expert):
Gnome 3 - Looks like Unity's identical twin, nuff said
KDE - Visually good looking but too slow for my old laptop (and I still use Windows on my main computer). Might be really good on a newer computer but I will have to leave testing that hypothesis for later.
Xfce - Ugly looking - and buggy first impression as it couldn’t access my encrypted home folder without giving some cryptic error message that had to be Google’d to understand what it means
LXDE - Didn’t like the default look (and too lazy to try to customize), and for some reason it also felt slower than Gnome 2 on my machine (despite the fact that it is supposed to be very light weight and therefore really fast)
In all fairness though, I did not spend more than maybe ~30 minutes trying each option, so these really are only first impressions and my conclusions might have been different had I spent more time with them.
Anyways, after having tried these on top of Ubuntu, I also found another distro called Linux Mint, which (at least on paper) seemed to be exactly what I had been looking for. It is based on Ubuntu and therefore should have everything that was so good about Ubuntu in the first place, but instead of Unity it ships with a customized version of Gnome 3 that is made to look more like Gnome 2 (with text based menus and everything).
So, I gave Linux Mint a quick try too, with the first impression being that it is visually very pleasing (even more so than Gnome 2), and with an interface closer to Gnome 2 it is much more usable than Unity or Gnome 3 for example.
It did seem a little buggy, however, with graphics getting messed up here and there rendering all text unreadable (never happened with Gnome 2 on the same hardware), Software Center locking up at times (could have been a user error though as I was trying to download updates and install new software at the same time, but again, this had never happened to me with Gnome 2), some programs (such as Chrome) not installing without cryptic error messages that required Googling to understand what they meant and how to fix them (though I’m not sure if this is a Mint specific issue either). It was also noticeably slower than Gnome 2, which is somewhat disappointing.
Overall I didn’t like any of these options as much as I had liked the old Ubuntu with Gnome 2, but since Gnome 2 won’t be supported in the future I wanted to make a choice sooner rather than later. And considering that I still liked Linux Mint better than any of the other options I tried, that’s what I will go with.