Nvidia Shield for sure if you need emulation.

No certified google/android tv box is gonna come with emulators pre-installed. You might find android boxes on aliexpress and the likes with pre-installed emulators, but you're gonna be watching streaming services at 480p due to the lack of certification and they're overpriced. Emulators are on the google store and are not hard to install though, just time consuming to configure.

Your best bet for a legit good android tv box would be the Nvidia Shield , but if I might add a better alternative, check for black friday Xbox Series S deals. I'm amazed to see it currently selling for $199 equivalent (i.e. Nvidia Shield MSRP). It no longer needs dev mode, so you can setup emulators from the get-go and it will run better than any android box. There are a ton of guides out there. For comparison, I believe on the nvidia Shield you'll be playing PS2 at the original resolution and (most?) games won't be running amazingly while on the Series S you'll be playing at 2k resolution minimum and most games can handle 4k with no compromises.

The only things you used to find with emulators pre installed is people selling pre configured raspberry pi with retro pie.

If you want good emulation of N64, Gamecube and PS2 games then the Nvidia Shield is the way to go, otherwise, any of the below list should provide good basic emulation (the Shield is included in the list):

CERTIFIED ANDROIDTV/GOOGLETV BOXES WITH NETFLIX AND PRIME VIDEO FOR THE UNITED STATES ONLY:

- AirTV Mini (More info at http://airtv.net/products )

- Directv Stream (More info at http://www.directv.com/stream/technology )

- Tivo Stream 4K (Dolby Vision & Atmos certified. More info at http://tivo.com/products/stream-4k )

- T-Mobile TVision HUB (More info at http://t-mobile.com/tvision/services/hub )

- Verizon Stream TV (AV1 hardware decoding. More info at http://verizon.com/home/accessories/verizon-stream-tv/ )

CERTIFIED ANDROIDTV/GOOGLETV BOXES WITH NETFLIX AND PRIME VIDEO FOR EUROPE ONLY:

- EKO KATV10 More info at http://www.eko-entertainment.com.au/katv10 )

- Homatics Box Q (More info at http://homatics.eu )

- Homatics Dongle Q (More info at http://homatics.eu )

- Nokia Streaming Box 8000 (More info at http://nokia.com/shop/streaming-devices/nokia-streaming-box-8000 ).

- Strong Leap-S1 (More info at http://strong.tv/en/products/ip-tv-receivers/leap-s1 )

- Youin (More info at http://weareyouin.com/en-es/p/you-box )

CERTIFIED ANDROIDTV/GOOGLETV BOXES WITH NETFLIX AND PRIME VIDEO FOR THE US, EUROPE AND THE REST OF THE WORLD:

- Chromecast with Google TV (Dolby Vision & Atmos certified. more info at http://tv.google )

- Realme stick with Google TV (AV1 hardware decoding. More info at http://buy.realme.com/in/goods/426 )

- Mecool KD3 stick with Google TV (AV1 hardware decoding. More info at http://mecoolonline.com where you can get a 10% off with the code "mecoolbox" at checkout)

- Dynalink TV dongle (More info at http://dynalink.life )

- Homatics Box R HD and 4K boxes and dongles (AV1 hardware decoding. 8GB of internal storage. More info at https://www.homatics.com?sca_ref=2766355.i6SwIDJJna )

- Homatic Box R 4K Plus (AV1 hardware decoding. Dolby Vision & Atmos certified. Gigabit ethernet. WiFi 6. 4GB of RAM. 32GB internal storage. More info at https://www.homatics.com?sca_ref=2766355.i6SwIDJJna )

- Mecool KD5 stick (AV1 hardware decoding. 1080p max resolution. More info at http://mecoolonline.com where you can get a 10% off with the code "mecoolbox" at checkout)

- Mecool KM2 Plus (AV1 hardware decoding. S905X4-B SoC for Dolby Digital Plus to Dolby Digital conversion. More info at http://mecoolonline.com where you can get a 10% off with the code "mecoolbox" at checkout)

- Nvidia Shield (The most expensive. Dolby Vision & Atmos certified. Gigabit ethernet. AI upscaling. Suitable for gaming. More info at http://nvidiashield.com )

- SkyStream Max (It's expensive. AV1 hardware decoding. 2GB of RAM and 16GB of internal storage. More info at http://skystreamx.com )

- Xiaomi Stick 4K (AV1 hardware decoding. Dolby Vision & Atmos certified. More info at http://www.mi.com/global/product/xiaomi-tv-stick-4k/ )

- Walmart Onn (More info at http://walmart.com )

CERTIFIED ANDROIDTV/GOOGLETV BOXES WITH ONLY PRIME VIDEO FOR THE US, EUROPE AND THE REST OF THE WORLD:

- Formuler GTV (Gigabit ethernet. Exclusive MYTVOnline2 app for IPTV. More info at http://formuler.tv/gtv )

WARNING!, ALTHOUGH MECOOL IS THE BEST OEM WHEN IT COMES TO RELEASING NEW DEVICES EVERY YEAR, THEY ARE THE WORST WHEN IT COMES TO RELEASING FIRMWARE UPDATES TO FIX BUGS AND ISSUES, IF YOU DON'T MIND ABOUT THAT, YOU CAN GET ANY OF THE FOLLOWING MODELS AT http://mecoolonline.com WHERE YOU CAN GET A 10% DISCOUNT WITH THE CODE "MECOOLBOX" AT CHECKOUT:

- Mecool KM6 Classic Edition (AV1 hardware decoding)

- Mecool KM6 Deluxe Edition (AV1 hardware decoding. Gigabit ethernet. WiFi 6. 4GB of RAM)

- Mecool KM7 (AV1 hardware decoding. 2GB/16GB and 4GB/64GB versions)

- Mecool KT1 (AV1 hardware decoding. DVB-T2/S2/C tuner built-in)

- Mecool Now (AV1 hardware decoding. Built-in camera and microphone for videoconferencing)

- Mecool KD2 stick (AV1 hardware decoding)

- Mecool HomePlus KA1 (AV1 hardware decoding. Built-in speaker. DVB-T2/C tuner built-in variant)

For more info about all certified Android TV devices, head over to www.androidtv-guide.com website.