You know how powerful marketing is when people are only considering Apple and Samsung when buying phones. To be honest I wouldn't recommend S4 or iPhones. There are other great phones out there you know...
My personal opinion on current phones on the market:
6.4" Sony Xperia Z Ultra: Best media consumption with biggest screen. Water resistant and has micro SD card slot. Great design.
5.7" Note 3: Best productivity (with built in stylus), most features and best all rounder. Big screen with removable back cover (changeable battery + micro SD card). Great battery life.
5.2" LG G2: Thinnest bezels with top specs. Great all rounder, up there with Note 3 and it has optical image stabilisation. No removable back cover and has ugly UI, buttons on the back. Great battery life. IMHO, very good for power users if you're going to install custom roms.
5" Sony Xperia Z1: 20.7 megapixel camera with water resistance and classy design. Non-removable back but spots a micro-sd card slot. Also very good all rounder.
4.7" HTC One: Best screen and sound. Aluminium unibody for premium feel and look. Non-removable back.
4.5" Lumia 1020: BEST CAMERA. Period. Excellent build quality and sleek, trendy design.
4" iPhone 5S: Most expensive. Ok, the camera is very good but Lumia 1020 wins by a very very long shot.
4" iPhone 5C: Best rip-off.