LLC Formation State for Real Estate Investing Help

Hi all, 

I am looking to form a LLC to invest my real estate properties under. I am based in NYC but I am looking to invest in properties elsewhere in other states. Should I be forming my LLC in my home state (NY), Delaware (LLC friendly) etc.? Would I need to register my LLC in all the states that I invest in? Any multiple state tax implications?

Lots of different information out there so if there are any legal experts here, would really appreciate your thoughts. Thank you!!