Anyways. From a user perspective you'll find that Ubuntu tries to make the Desktop "easier" to use. It releases new versions every 6 months and it's of course free. Free as in Freedom, and free as in beer. To a lot of people that really matters
there are literally hundreds of versions of GNU/Linux operating systems out there. In general I think Ubuntu is the best to start with, but after a while people ususally branch out and try new things
Anyways, it's easier to point out negatives than positives
Games. This used to be a really big drawback, but now there's Steam for Linux and they're constantly adding more compatible games to their library. People will say "Oh just use this WINE thing" but it's a workaround and not a native solution. Yes, some games will work but odds are it won't be 100% windows fun
WINE is a "windows compatibility layer", so it's the communities attempt to translate windows binaries to be compatible with Linux. To their credit a lot of stuff works pretty well with WINE. Like for me Photoshop was a show stopper but I've got that with WINE now so it's OK
IMO It's still a negative because it's a workaround
You can checkout the application compatibility at the WINE HQ App DB
Finally, the vast majority of peripherals work, like mice, cameras, drives, whatever. One sore spot that is always improving but still lags behind in hardware compatiblity are Printers (most all work, but newer printers tend to lag behind), some WiFi devices (mainly broadcom), and the occasional graphics cards
Debian family (Ubuntu, and such) are my preferable choices. Starting out I think Ubuntu is likely by in far the easiest to use. You can try other family of Linux OS but really what you want to try out are different Desktop Environments
So, Ubuntu uses Unity (in the screenshot above), but there are hundreds of other just Desktop Environments that change the way you interact with your computer.
There's two parts to that, no need to dive in too much, but Gnome is a set of libraries for rendering stuff, and they released a Desktop Environment they call Shell, you'll likely just see it referred to as Gnome