iPhone 6/6 Plus: Probably wait, unless you’re the kind that really needs that rose gold, or are allured by the idea of 3D touching your phone. It’s an interesting upgrade, but will you be able to resist the new design next year? Let’s be honest: no.
iPhone 5s: It’s been two years since you upgraded, so now’s your chance to get last year’s design with this year’s internals. The ‘s’ release usually means the kinks are ironed out and you’ll enjoy it without issue for a long time.
iPhone 4/4s/5: I can’t believe you’re even asking. Do it! Just click here and blindly throw money in Apple’s direction.
Android: Looking for a great camera, good performance and something a little nicer to look at? iPhone 6s might be for you — Apple even made an app to help you move across to the dark side.
Windows Phone: Microsoft’s flagship event is on the horizon… but you can’t fix the lack of apps in a day.