Today most people buy split AC on the basis of their features and specifications. Electricity consumption has almost escaped from the list of deciding factors. Below is the link to the site where you can see the ranking of different AC's based on their electricity consumption. This ranking is provided by BEE (Bureau of Energy Efficiency).
Some of the features you should consider while buying an Air Conditioner
Reverse Cycle: Most of the AC these days come with reverse cycle. That means that it cools in summer and provide heat in winters. So always prefer to buy such AC as it will work in both summers and winter.
Remote Control: AC should have remote control system which makes it easier for you to switch the level while resting on your bed. Previously built AC's didn't had this facility and you had to manually change the level of AC.
Timer: Now most of the latest AC comes with timer. Once you return from office, the AC understand the time set by you and starts automatically.
Eco Mode: Energy saving mode is yet another service that you should look into an AC while buying it. It saves energy and minimizes your electricity bill.