Over the past 5 years I have bought and used almost every tablet since the original iPad and I have found over the past year that I pretty much exclusively use the Surface Pro and Nexus 7 with the iPad, Kindle Fire and Surface RT starting to collect dust.
These two devices cover everything: Surface Pro is the perfect couch and desk computer and the Nexus 7 is the perfect commuter/reading tablet. I do still turn on the iPad and Surface RT when new updates come out and play with them for a couple of days, but then I just settle back into my normal routine of the Pro and Nexus 7.
To be fair, the new iPad mini looks like it could replace my Nexus 7 in uses but I feel more comfortable taking my Nexus 7 to the beach, pool, hot tub and in the rain because it is so low cost. I will definitely get the new Mini and try it though.
As for the Surface Pro, there really is no competition. Crazy to believe it is the only tablet to make a useable kickstand this far into the game, plus all the goodness that comes with running pen based desktop apps and having an awesome keyboard solution.
Will be interesting to see how this next year plays out, but to me these two devices have distinct advantages that really set them above the competition. Pro with its value in versatility and Nexus in its performance at an unbeatable price point.