A lot depends on what operating system you want. Once users get a phone with a particular OS they tend to stay with that family of phones so in that way OS choice is probably more important than the phone itself. If you want an Apple iOS device you are looking at either an iPhone 5 or iPhone 4S (if price is a concern the 4S is still a great phone and cheap). If you go with Android or Windows phones you have a lot more choices. For Android phones the Samsung Galaxy S III is a popular choice and if you want a Windows phone the Nokia Lumina 920 seems to be the hot ticket.
Depends.... - do you need multiple functions such as camera, touch screen, apps, navigation, e-mail, calendar, keyboard... or do you want a plain phone to make calls with? - how important is battery time? - how important is stability of the product (waterproof, shock-resistant, longevity)? - how important is product/brand image / status symbol? - how much are you willing to pay?
Or short... da you need a phone to use at a dusty, dirty construction site? Or do you need a phone to use in the office?
There is no real "best" there is only what you like.... Personally if the S3 mini was around its earlier expected price of 250$ it would be THE best phone around (price compared to tech wise anyway)
That will based on ur budget what u have bro....