I need to buy a new wireless Internet router. Which type gives the fastest connection to devices.

The fastest connection to multiple devices is provided by routers that meet wireless standard 802.11ac, which is intended for applications such as streaming HD to multiple users. Make sure the one you get is also backwards compatible with older standards 802.11a/b/g/n as well so that older Wifi devices can use it. However, your speed will depend not only on the technology of the router but also the WiFi capabilities of your device(s), as well as the specifics of your physical environment (such as the distance between devices, presence of interfering walls and floors, etc ).

I've had a Cisco Linksys E1200 for about 5 years, and it's always been reliable. A roommate upstairs a good 70' away at the far end of the house asked me to move it slightly once.
As for speed... doesn't your service provider determine speed quite a bit? I live in the middle of nowhere with cable, and I think the length of the cable from the road, on down the line, has a lot to do with it.

Joy - yes, your speed of internet connection is limited by what your internet service provider delivers to your house, which in turn is dependent on the the specific plan you are paying for and perhaps also by the condition and demand on the network (including the number of simulataneous users in your neighborhood, especially if you have a cable internet provider). The length of the outside plant cable is generally a concern only if you are buying DSL from the phone company, although if you have an especially long drop from the street to your modem cable internet can suffer as well. It's important that if you are paying for 20 Mb/s downloads you should to check the speed of your connection to make sure you are getting what you pay for (there are free apps that can do that for you). Such a test should be done using a PC that is physically attached to the cable modem, as opposed to one operating over your Wifi network.

thanks ebaines