OK, man this is a tough question. I have been through several android phones in the past year. Motorola Razr Maxx HD. Galaxy S3. Droid DNA. Despite the not always lots of fun battery life of the S3 it's emerged as my favorite. The display to me is as good as the DNA and much better than the MaxxHD. It just works. Everything always just works, unlike the somewhat buggy DNA. I'd like a faster camera and more battery, but it's hard to think of what else I'd improve on the S3. I have been reading all the reports on the new Blackberry Z10 and I am very definitely a BB fanboy - I want that Z10. But man, this S3 is a good phone. If the S4 fixes some of the minor shortcomings of the S3, then I may just go with it pretty quickly after release - and of course I will be following the new users very closely on Android Central.
And now that I typed all that I find myself thinking the BB Z10 with that cool new OS might be a good change from Android. I don't know. It depends on which way my internal wind is blowing. If BB leaves the door open for customization via themes as they used to or as Android does with launchers, then I think it will be the Z. That's one reason I went away from iOS - it's usable, reliable, and BORING.