for a bedroom split or window AC will be best.I want 1.5 tonn AC for my bedroom. Which brand will be better?

kind of AC depends on the design of your bedroom and also if the house is rented or own house.

(for own house) see if you have provision for AC in the room like a window space etc... else you can get it created, then window AC is fine....

(for rented house) better to take spilt AC as you dont know when you can move to another house and provision may or maynot be there to create window space, also landlord may have issues in this, bcoz most of the time it required repair job.

Cooling wise, i've both kind of AC in my house, they both work equally well

split or window AC is designed in accordance to the requirement of the buyer. in case you have area, then choose for window, if no longer, then you definately have not got any decision yet split. split ACs look appealing, yet they call for maintainance. window ACs are tough and hard, uncomplicated to maintain. in India Voltas is giving stable high quality. LG's ACs are greater inexpensive. decision is all yours.