I’m going to assume that you’ve already made you mind up on taking the Android plunge or already have and want to upgrade or add a device (smartphone/tablet). With this in mind my advice will be succinctly simple; buy a flagship device. Every device manufacturer will have one that easily rises above all others in prestige, options, marketing, and of course price. Can’t afford one? Save until you can. Why? Again very simple, because of support. Many device manufacturers customize the basic Android software for their phones or tablets. Why is debatable, what’s important is these are usually device specific customizations so if you want to stay current on software and updates your best bet is to simply stick with a flagship phone because theoretically they will be treated with top priority regarding support and software updates. Not sure which manufacturer to go with and whose customization is the best then please visit CNET.com to access indepth reviews for best cell phones and best tablets. One last piece of advice go hands on with one at a store and play with the interface and see what suits you best. It might be worth noting my personal opinion is that the one who pays most attention to the quality of hardware cares the most about your experience. With that in mind my personal favs right now are the HTC One smartphone with it’s svelte aluminum body and the Nexus 7 tablet for it’s pure Android experience and its killer price to feature ratio.
Updated 5/8/13: It’s pretty much become a two horse race on the Android smartphone front between Samsung and HTC (that is until Motorola shows itself again since being purchased by Google). Check out this great article pitting both manufacturer’s flagship phones head to head-HTC ONE vs Samsung Galaxy S4.