Well, do you want android or windows 8? Do you want easily portable or does it matter. Do you have $1000 to easily spare? If you play PC games, the Sony windows 8 would be a good choice IMO.
If you want to sit back in comfort and browse the internet or watch a movie, the Nexus 10 would be a good choice. As far as surfing the net, my Nexus 10 is about as fast as my laptop. It also has a beautiful screen.
You might also consider buying nothing now and waiting for the newer windows 8 hybrid laptops that you can also use as a tablet.
It really just depends on your budget, your tastes and when do you want it.
Since this is about android and windows 8, tablets and laptops, I'll move this to the lounge so you can get more opinions.