Probably this one. Still going strong 2 years later.

Funny reading the 7 comments. That was easily my worst iPhone ever. Damn thing didn’t make it 2 years before complete system failure in every way possible. Started of with weird haptic feedback. Felt and sounded like a broken spring, then battery swole, phone split and bent, and eventually it no longer functioned. Also the only phone to completely die. The rest I just wanted a new phone.