Google Nexus 4 over Galaxy S III
Stock Android, quick updates
Next generation CPU and GPU architectures, 2GB RAM on all models
Unofficial, limited LTE connectivity
Competitive price
Full RGB strip IPS Plus screen
Gorilla Glass 2 on the back, eye-catching pattern
Samsung Galaxy S III over Nexus 4
Better camera
16:9 Super AMOLED screen
More storage options, microSD card slot
User-removable battery
USB OTG out of the box
Plenty of software perks (MultiView, Smart stay, excellent codec support and more)
Color options
FM Radio
Readily available in stores, steady price
http://www.gsmarena.com/google_nexus_4_vs_samsung_galaxy_s_iii-review-864.php