I was born in 88, so these choices happened in the early 90s
Yankees- Dad is a Yanks, Mom is a Mets fan. Picked the Yankees
Giants- Dad is a Giants fan, Mom is Jets. I picked the Giants
Rangers- Whole family is Rangers fans so there was no decision there
Nets- This one is different. Dad grew up in Upstate NY, so he's a Celtics fan. As a kid I was an MJ fan, never really picked a team and just rooted for Jordan. When he retired I decided to finally pick a team. I wasn't picking the Celtics, couldn't root for a Boston team. I could never root for the Knicks because of all those Jordan matchups, I hated them. So there was only 1 other local team, and the Nets became my team during the 98-99 lockout season.