Router

Most router are solid these days I would say save your money and go off brand.

If you are looking for the best router most 802.11ac are gonna work

Linksys EA8500 Max-Stream AC2600 MU-MIMO Gigabit Router
OR
Asus AC2400 RT-AC87U Dual-band Wireless

Cheers I like the MIMO by Linksys my self.
 
What is the best router to buy wifi.

Well, that might depend on your location, the size of your residence, your internet provider speed and if how your budget relates to the purchase price. Buying used can really help with all of these factors as it allows for a better router for less money. Some prefer to use the gateway/modem/router that their internet provider provides....some don't. I bought a Netgear Nighthawk 7000 used and then downloaded DD-WRT R7000 firmware to get away from Netgear's Genie crap. It provides what I need for a lot of different hardware connecting without any extenders or switches.