I recently wrote a post introducing two british characters, both of them speak in english accents. The RP is currently in a period where all of the members have creative control over the posts and a bunch of us have been adding NPC's simply because it makes the story as well as writing much more fun. 

[hider=post]
Toby and Namine chased the item box as it flew through the air. Both of them managed to catch up to the item, simultaneously grabbing the box as they sped through the air parallel to eachother, moving at the same pace. Both riders now found themselves playing tug of war with the item box. "You're lucky I promised my mom I wouldn't hit girls!" Toby shouted and began to pull with all of his strength. "Yeah? Well you're lucky my hands are on this box, otherwise i'd punch you right in the throat-WHOA!" As Namine yelled her comeback at the boy, he intentionally released his grip on the box, causing the girl to spin 360 degrees on her hoverboard. As gravity brought Namine back to an upright position she was momentarily disoriented whilst attempting to regain her balance "Son of a carrot" She muttered. Toby didn't hesitate to snatch the item from her hands. 

"Mine!" He shouted with joy, where as the girl immediately bent down, grabbing his hoverboard and pulling it from beneath him, causing Toby to reel backwards and release his grip of the item allowing Namine to take possession of the box once more "Mine," She said in a sarcastic tone as to mock the boy. Toby once again found himself flying upside down. A troublesome smirk overcame him once more as he suddenly spun himself in a circle whilst flying upside down, using his hoverboard to launch the item out of Namine's hands through the air and into another riders possession. 

[center][img=http://i.imgur.com/f9tpTwX.jpg][/center]

[center][img=http://i.imgur.com/ln7YTk3.jpg][/center]

"Hm? Yves, seem's an item box has made it's way into your hands."

"It appears so. Today must be my lucky day." Yves studied the item box in his hands curiously, as if he was intrigued by it's presence. "Out of all the days. I'd say that's quite fortunate, wouldn't you Landon?" 

"Quite fortunate indeed" 

The two seasoned veterans spoke in what seemed to be english accents. Both Landon and Yves intentionally decided to pull back from the lead as to avoid the mayhem caused by Ace. The two were a perfect example of the saying "slow and steady wins the race," and took the competition a bit too serious. Yves waited patiently for the slot machine to come to a stop. Once it did, his face remained blank, as did Landon's. Even so there was still a hint of arrogance surrounding the two. 

"Not a bad item," Landon said, Yves gave the box a look of distaste, "It would've been much more useful had I obtained it earlier,"

Toby eventually regained his posture and balance, the boy was quite irritated, even to the point where his cheeks were starting to turn a little red. "Hey! Numbskull! That's my item!" He shouted and with haste began to ascend towards Yves, blinded by his sudden obsession to claim the item box for himself. Namine's eyes suddenly grew wide as she realized what item the box had provided. "Wait, hey stop! Stay away from him!"

"Mine as well use it now," Yves spoke in a non-chalant tone and turned his attention towards Toby, aiming what appeared to be [url=http://i.imgur.com/lFHZDTD.jpg]some type of pistol[/url] in his right hand. "I'm really kinda getting super annoyed, I saw it first an-OH! Oh geez, what is that?" Steam began to shoot out of two holes in the pistol which began to make a sound similar to that of a teapot whistling. The sound of a gunshot shook the audience as a [url=http://i.imgur.com/SBBN4M2.jpg]pointed bullet[/url] whizzed through the air and lodged itself into Toby's hoverboard. Within moments the hoverboard began to shoot out steam as well and gradually started slowing down. "Oh no, oh no no no come on, what did you do!" The pointed bullet damaged the mechanism that allowed the hoverboards to actually hover. "Poor fool," Landon remarked, he and Yves sped off as Toby made the slow and inevitable journey to the ground. He began to curse profusely.[/hider]

In my opinion the two characters somewhat added a little bit of variety due to their uptight, no nonsense intellectual attitude, where as the other characters are all eccentric, silly and generally cheery. The accent wasn't necessary, but I feel like it helped distinguish not only the way they sounded and appeared from the other characters but also their personality.I think effectively making a character seem unique or different from other characters solely depends on the context of the story at the time as well as the other characters. If Landon and Yves spoke like the rest of the characters, they would probably come off as narcissistic jerks, however because of their english accent's they instead come off as intellectual snobs. 

Is this stereotypical? No. At least, not in the context of this story, which takes place in a world where tree's talk and donuts dance. England doesn't even exist in this story, but the accents distinguish the characters effectively because they are currently the only ones that speak in english accents. 

TL;DR [u]in my opinion[/u] writing and giving characters accents being a good idea depends on the context of the story. Does it make sense for this character to have an accent? Does it effectively distinguish your character from the others? What accent is he/she/it speaking in? All depends on the context, heh.