My favorite Apple Reseller store in terms of service is Ascend Zone @ The Curve, Mutiara Damansara. I've sent in a lot of repairs for my Mac there and the work quality is excellent. Sadly I think they're either closed or have moved somewhere due to slow business.

I think as for right now, EpiCentre The Pavilion provides the best service and customer loyalty programme. They have discounts for accessories for members and also education discounts.