It's okay from what I can tell, still not sure why people call it the worst linux distro out there but I haven't really done anything with it except web browsing, playing games that are compatible with the OS, and some other things.
I'm trying it on on My Desktop as as type this. for some reason it won't let me try it out on my Dell Venue 8 Pro even though I've disabled Secure boot. Either way I Really don't like Unity after using it for about 5 minutes. lol
Unity is good for screens with limited hight, like a laptop. Once you get your head around the GUI it can be very efficient and aid work-flow. Especially if you are the type of person that likes to use the keyboard. Using scopes for searching for programs and files. The often over looked dash for quick access to menu items within programs. It may be the best GUI for laptop use, the combination of good use of vertical hight on screen or bias towards the keyboard over the mouse given issues many have with track-pads.
Now everything is not perfect in Ubuntu's world. They have spent so much time over the last couple of years on the mobile and cloud versions that the desktop has been starved of development. This doesn't mean it's bad just has stood still. Standing still for a Linux distro is quite unusual, one of the stand out features of running Linux on your computer is that the pace of development is so rapid there is always something interesting going on.
If you are interested in Ubuntu there are always the different spins. There is the obvious difference is each one has a different Desktop Environment. So if Unity is not to your taste then may be kde or Gnome is. The less obvious difference is that they are just that little bit removed from Canonical. They tend to have more of a traditional community feel that many of us Linux users are more comfortable with.
There are really good reasons to choose to go with the Ubuntu base but you might find it more comfortable with one of the other DE's.
I don't think anyone should recommend an older version of Linux. If it that old school feel you are after the have a look at Ubuntu-Mate. My Go-To Debian based Distro is SolydXK, but Ubuntu-Mate comes a close second.
My favorite distro by far is Mint. I like the Cinnamon UI and it runs super fast. I have noticed some considerable lag in Ubuntu lately, even on my gaming machine.
Honestly Sabayon is what I'd recommend. I myself have yet to tamper with the depths of Gentoo. If you want to learn a crap ton in a few hours pure Gentoo or Funtoo is where you go.
I haven't used it in a couple of iterations but it used to be one of the easiest versions of linux to learn. I know in the past few years there have been a lot of new distros gain popularity amongst ex windows users. Next time I feel like dabbling with linux I will probably go with debian.
For a desktop, I am torn between Debian and GNOME3 and Linux Mint. They are both great and very efficient. They both have great support. But in a server setting, I don't think I'll ever use anything except Debian and possibly CentOS. For a while I used Ubuntu Server, and hated it. Then I found out how incredibly simple and user friendly a Debian box with Webmin can be. I've not looked back since, and I keep telling myself I need to mess with CentOS but I just can't find a reason to leave Debian. I guess if I was deploying a bunch of web servers and needed something that doesn't need updates constantly, maybe. But for everything I need, Debian (or some variant of it, looking at you Linux Mint) is like Linux from angels.
A year ago, I would've said the same thing. Then Lubuntu started requiring PAE, and having worse and worse software support. I have since tried Debian, with GNOME classic and LXDE and XFCE. After trying that, I have come to the conclusion that GNOME classic is my favorite lightweight DE. For a quick, uber light DE just to run some basic stuff, LXDE works fine, but GNOME classic is just so awesome. I use it on a Linux laptop of mine, heck, I've even stripped it down quite a bit and idiot proofed a Debian install for my grandma, which I support via TeamViewer and SSH from 8 hours away. Works flawlessly.
Debian+LXDE=The bare minimum GUI
Debian+GNOME classic=perfect combination of light and still capable