Wanna throw it in tags and completely spoil it for me? :P

Okie dokie lokie!

Nightmare Rarity spoilers below:
Basically, the Nightmare forces preyed on Rarity's personal self doubts (Specifically choosing to target Rarity) and weakness (Dash and AJ are incredibly athletic and strong, Fluttershy, despite being timid, will do anything for a friend, regardless how scared or at whatever risk to herself, Pinkie's eternal optimism keeps her level headed in a bad situation, and Twi is one of the strongest magic users in Equestria, leaving Rarity as the "Odd man out" so to speak), and overtook and convinced her that the other 5 would replace her with any other pony as both their friend and the element of Generosity the first chance they could.

This is what the Nightmare forces did to Luna a thousand years prior, taking Luna's own depression for how the other ponies reacted to her night and amplified it, convincing her that Celestia and the others didn't care for Luna.
This is where Sweetie Belle played a part. She didn't save Rarity, but Luna. When Nightmare Rarity came down to conquer Equestria, Luna felt it was her fault the Nightmare forces are even a threat and tried to confront them. It was through Sweetie Belle and Celestia that Luna learned that everypony loved her and weren't angry over her actions as Nightmare Moon.

Rarity was saved through the mane 6. The Nightmare forces convinced Rarity that the others saw her as worthless, and even when Rarity was separated from Nightmare Rarity (Thanks to the efforts of Spike, who went through hell and back to even get through to her), the self doubt was still clouding her mind. It took the remainder of the mane 6 to remind her that all her friends loved her, and that they'd never replace her through memories of good times they shared. This reinvigorated Rarity's spirit and removed the negative emotions and lies the Nightmare forces were feeding her to sustain itself. It was a rather endearing and touching scene. Brought a smile to my face.

So, in short, the Nightmare forces were hoisted by their own petard (I didn't get into that, but the Nightmare army itself was defeated through betrayal), Luna was saved by Sweetie Belle and Celestia, and Rarity was saved by her friends. I didn't detail everything Spike went through, but he was more of a main character in this arc than Twilight, which was also pretty cool.

Been watching MLP again and well my mum worked while watching and I gave her on my phone the brony meaning on urban dictionary

I should start watching MLP again, because why the hell not :p

Oh, and how did she react?

I looked up the Japanese dub of Suited for Success and Winter Wrap Up because I wanted to hear how Art of the Dress and the Winter Wrap Up song sounded in Japanese... Needless to say I was rather disappointed to find that they didn't re-dub them. :(

I haven't watched MLP since the S3 finale, i can't find it in me to watch reruns.

Yeah. It sucks that they gave up on re-dubbing the songs after Giggle at the Ghosties.

Why not?
Afraid you'll have another opinion on the finale you never intended to enjoy to begin with? :I

gave me a weird look and told me not to tell any one

http://fc03.deviantart.net/fs71/f/20...ta-d4cwywx.jpg

Dr whoos Strikes again and i think i found my new sig

https://sphotos-b-ord.xx.fbcdn.net/h...41602335_n.jpg
Not a fan of Doctor Who, but I can always enjoy a shout out or reference :p