I have both WD and Apple TV
Apple TV is great for streaming stuff but only if you have an Apple device
WD TV is an all rounder especially if you have a newer one
Roku is the best overall if you can get one
Dont listen to the other guy, Amkette,iRevo etc are poor quality and lack application support
Apple TV,WD and Roku support tonnes of apps from your exisiting devices
Worst case scenario, Raspberry Pi 2 is worth considering but beware its not as cheap as people think
A setup with RPi2 from scratch can cost 7-8k minimum and needs alot of workarounds though its very flexible if you are adventurous
otherwise Apple TV,Roku and WD are the best , no nonsense devices
@OP: there is gBox available online which also looks good.
if u want to import from overseas then there are tons of options available MiniX 8H Neo etc etc.
don't go 4K now as it will take time to settle in and remember all HDMI 2.0 with HDCP complaint is mandatory for 4K support in future
so almost all old streaming players don't support & not eligible for 4K.
as of now my current choice will be Nvidia Shield Android which is future proof but costly (20k if bought from Amazon.com)