Planning

Ok, my plan to stop hopping is to stay with the same distribution from around a mont, even if I'm bored.
To avoid downloading thousands of distros, I'll decide between the following:

• Ubuntu, at the moment 12.04. I'll just ignore 12.10, plus people says 13.04 will be much better.
• Kubuntu, not needed to ignore any version. Is my current distro.
• Xubuntu, also the last version available. Like the "fallback" one, if any of the others work decently, this always does.

And those are all my choices.
Now, why?

Ubuntu

People hate Unity, I really like it. I just hate Compiz, it's the cause of most Unity's bugs. Ubuntu 12.04, with Unity, is much more stable than 12.10. In fact, I haven't had any crash on 12.04, so that would be my version of choice at the moment.

Kubuntu

I've never been a KDE boy, but I've used it sometimes, and liked it. I stopped using it because of it's very heavy on resources, specially with KWin effects. KDE 4.10, though, has a much better performance, and you can happily disable some effects, in my case the minimizating ones. If you do that on my computer, KDE will be as quick as Xfce, I'd say! It's much more resource hungry than Unity and, of course, Xfce. Idleing with Chromium (without Flash), Quassel and a Terminal, 10% of CPU (2,00GHz I have)... On Xfce it's ~5% with Flash! 

Even though, KDE won't crash, as its CPU is high but constant, not like Unity which goes up and down and causes crashes.

Xubuntu

My fallback distribution. It always works for me, I never had a problem with it! Besides that, it's a bit too lightweight for me; KDE has more features, Unity has better looks. So I preffer trying them, but if in the end any of those are my choice, Xubuntu will be...

Actually...

Actually, I'm on Kubuntu 12.10 with KDE 4.10. I'll try to stay there for about a month. Here's my Unity-like desktop (thanks phunyguy for the idea!).

My current desktop!