Hey there,
I don't think there is a 'best' smart phone in general. It greatly depends on your requirements and the money you'd like to spend on your new device.
Take the nexus 4 as an example, for many it's one of the best devices at the moment. But if you need a removable battery, expandable memory or 4G network connectivity, you won't even consider a purchase of the nexus 4.
Here are some phones you could be interested in, but there are hundreds of others...
Google Nexus 4, Samsung Galaxy S3, HTC One S, Samsung Galaxy Note 2, Sony Xperia U
Cheers