The NVIDIA Shield is a good challenger to the Nexus Player and Razer Forge TV. But, the Android TV is quite expensive. If you are looking for a cheaper offering, you can grab the Nexus Player from Amazon.
The retailer has listed the original Nexus Player for a price tag of $64.78, which is a discount of $35 on the retail price of $100. The members of Amazon Prime can avail this Android TV in just two days without any additional shipping charge. This does not seem to be a limited sale and so the price of the Nexus Player will be low for a while.
The Nexus Player is compatible with the newly released Android M Developer Preview that brings support to Bluetooth A2DP audio streaming and external USB storage. The Nexus Player based on Intel hardware could be sluggish while playing games and using applications as it is not optimized properly.
At this pricing, the non-Android alternatives are limited to the Roku 2 featuring an improved media app selection and Amazon Instant Video and the refurbished Roku 3 with headphone jack on the remote.