There is no true specific brands popular. Now you can see 7/10 teens are wearing Plastic frames(The glossier ones) which can easily be brought @ Pasar Malam/77th street mostly. RayBan is popular due to their Wayfarer designs and their Sunglasses,nothing more. Oakley is Durable and they have a longer warrenty(if i'm not mistaken).
If you wanna follow the trend but be different,i would recommend Frames like a Half Plastic frame(Similar to the half frame metal type,but in plastic) , Matte coloured , Half wayfarer design(Like RayBan's) , or any other types which suits your face shapes,exotic or simply you favour them and those which 'stands out' to you.
Don't ever just follow the trend blindly and choosing one that you don't like. Even if the frame that you like is not the 'trend' , Don't be afraid,just buy it if you really like it and let the others follow you instead. You might be the next trend.
One more impt factor is Self-Confidence ; If you don't feel 'secure' in that pair of specs,change it. Rather than living everyday with the feeling that people's staring at your 'What-seem-to-be-wierd' combination of your specs and ur face. A specs is more than a accessory,its a statement which shouts out loudly who you are and what are your 'tastes'. Its a need for you to wear everyday. And you must be comfortable in them.
Oh Oh! I don't know if you know,but there are these really simplistic and lightweight specs in town(actually most spec shops) and they are sooo cute that they cost a bomb. I will upload some pics of it tmr night after i get more info about it , so stay tuned!! =D
Damn skool . . .