The American Museum of Natural History is well known. It's quite big, spanning four floors filled with exhibits and a planetarium. Many people visit here daily, so be prepared for crowds and long lines, especially at the ticket kiosk. The museum is split between exhibits that are included in the general admission and exhibits that have additional fees, so plan for that.

Museum admission is around $25-50$, depending on whether you want to look at the ticketed exhibitions, and parking starts at $33 for up to 2 hours