Okay okay okay everyone loving stop.
Please.
Just, loving, shut the forget up for one moment.
I just want everyone to acknowledge the fact
for once that there is no one distro that is definitively better than the other, because all everyone ever does on these damned forums when linux pops up is throw some incredibly one-sided opinion at what someone should use just because
they like it.
A couple of helpful links:
http://dictionary.reference.com/browse/preferences?s=thttp://dictionary.reference.com/browse/opinion?s=t&ld=1133A distro shouldn't be used because it's popular. A distro shouldn't be used because it's the fastest. A distro shouldn't be used because its the most lightweight. Don't act as if there are only one or two distros in existance and all others are minorities not to be considered. Ask what the OP wants or needs in an OS, and suggest something that is tailored to their specific needs. If you can't answer this question, I kindly suggest you get the forget out.
Jesus christ.
Massive rant aside, the computer OP has probably wouldn't play well with a relatively heavy distro like Ubuntu. From my experience, speed and memory usage depends mainly on a. the desktop environment, and b. already installed programs, and Ubuntu's many default applications and Unity pretty much fails in these two aspects. The only plus is if you're looking for something different, or if you just want more linux-based applications to work for you.
However, Ubuntu works very well as a stable basis for an operating system, which is why there are so many variants (Xubuntu, Lubuntu, Kubuntu, Linux Mint). You can still have a (relatively) stable operating system, all the while staying high on speed and low on resource usage. Xubuntu (with XFCE) and Lubuntu (with LXDE) are both very good choices if you're looking to go onto the speedy side of the spectrum, and judging by your specs, that seems like a very good route to take, as Ubuntu's aesthetics aren't worth the speed loss. Avoid Kubuntu, as the desktop environment (KDE) is about as far from lightweight as OS X.
As you're a beginner, only use distros like Arch or Gentoo if you're really,
really adventurous. There are a lot of tutorials available, but the setup time and the effort required to get and stay running isn't really worth it when easier, more feasible solutions are available. Yes, they do run fast, and they're good for systems like yours, but you should still start small.
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