Buy Xperia Z if you love "L";
Buy Galaxy S4 if you're against children rape;
Buy an Iphone if you want to wake up in the morning to find that Illuminati took your consoles.

I think the main advantage of Android is it's openness. There are a plethora of launchers, widgets, themes, and custom ROMs to play around with to make your phone exactly how you want it to be. It also has Neutron Music Player. Nothing, in my experience, can compare to improved audio quality that app brings to the table.

The GS4 is an (overly)powerful phone, so you shouldn't] be experiencing any performance hitches. Unfortunately, something about Android seems to induce lag in even the strongest of phones, so the chances are you actually will run into some stutter now and then. Nothing major, though. It's also got a Super Ultra Fantabulastically High Res Amoled screen(or w/e they're calling it these days).

Wait iPhone 5S like me.

I would, but I'm really not sure if it will feel fresh again. iOS 7 looks reasonably cool, but I just feel the OS is getting kinda dated.

All I can say is skip Windows phones for a while. They are still not up to standards.

I liked the news things in the iOS... and the controller support will be killer (not because the support itself but because iOS have better games than Android like FFs).

HTC one all the way.  I just got the phone and it is easily one of the best phones I have ever had.  I've seen/read/heard nothing but good things about it.  As long as HTC can start bringing out this same quality with all of their phones from here on out then I will be sticking with them. 

OT: If those are the only ones you're considering I would go with Galaxy S4.  Leagues better than iphone, imo.  Same with the HTC one.  Was cautious about leaving iphone for the htc one, but I'm never looking back.

I have never heard of the HTC One. I'll look it up.

Most websites I've been to and the people at my AT&T store have said that the galaxy s4 and htc one are the two best phones on the market right now.  I'm slowly converting my family to it.  My dad and my brother both want to buy it.

HTC One and Galaxy S4 are the best phones out there in my opinion.