My Dad grew up in New Jersey and was a big Rangers fan before the Devils existed. Then in 1982, he did the unthinkable and switched from being a Rangers fan to a Devils fan, and has been a Devils fan ever since. He's taken a lot of crap from his friends over the years about it lol.
As for me, I was born/raised in Jersey, but have always been a Rangers fan (the first two games I ever attended were at MSG for the Rangers, and it stuck with me). Moved down to the Charlotte, NC metro area 16 years ago, but I couldn't imagine changing from being a Rangers, Jets, and Yankees fan. I'll pull for the Canes when it doesn't involve the Rangers, which was a lot easier prior to the 2013 realignment. And I'll pull for the Carolina Panthers as long as they're not playing the Jets or Giants because they're the local team. The locals here are all Braves fans, and I could never root for them.