Please suggest a good, low budget Gamepad for Thomson Android Tv

I bought a Thomson Android Tv and have tried installing and running a few racing games for my child from the Google Play Store. However, almost all of the good games need a Gamepad to play them. My son wants to play these games on TV but cannot do that as he doesn't have a Gamepad.

So, please suggest a good Gamepad that will work with an Android Tv. Just to mention that I am looking for a low budget but good Gamepad. If available online, you may also post a link. Thank you.