Most Plp would def say Yonex. As you are a novice i think u should try brands like Forza,Carlton,Fleet,Fischer and stuff like that B4 coming to Yonex. If u have a Yang Yang SSP 900 then u probably have a great racket.(Plp claim it performs at the same level as the Iso 900) So go ahead and give it a shot! Try a lot of brands B4 buying Yonex!
Most people would go for Yonex or Carlton. These 2 brands in my opinion are the top 2 in badminton products, Yonex first and Carlton a distant 2nd. Though Yonex products are often more expensive than others, it would be a good idea to explore other brands as well. Personally, i'm a Yonex user and i'm happy with the rackets i'm using.
I think Yang Yang is a good brand. I have a Tactic 9000; it suits me really well and is pretty tough. The quality is a little lower then of Yonex. I don't think there is a best brand, only a popular one. Anyways, it depends on the racket.
Ehem... I thought you were a sponsored player... sponsored by Winex? You're supposed to be promoting Winex goods aren't you?
You're right Quantum. There is only popular brands... there is no one particular best brand available. Only individual racquets that suit different people's needs. The best racquet is the one you feel most comfortable with, and that you can perform with best.