For my fictional capital city of Union City on OpenGeofiction, I use the following:
Dividers:
Independence Blvd (0E-W)
Capitol St (0N-S)
E-W streets: Presidents in order from President St (1300 S) going north to Obama St except for Capitol St and the 2 east-west streets that make up Union Circle Square. The southern street is Harpo St and the northern street is Groucho St. South of President St, there's only a couple blocks before the ocean. Those streets are other famous last names. North of Obama St, the names are more random last names.
N-S avenues: West of Independence Blvd, the streets are named for states, except for the western boundary of Union Circle Square named Zeppo Ave (400 W), working west to east and north to south in order. After the states, then territories. At Western Ave (5800 W), the names are random first names. East of Independence Blvd, the streets are named for the state capitals in state name order. Montgomery, Juneau, Phoenix, etc. except for the eastern boundary of Union Circle Square named Chico Ave (400 E). When a capital shares the name with a President, the President street takes the name and the avenue is named after another city in that state. Biloxi, St Louis, Omaha and Milwaukee were used. Then comes Eastern Ave (5100 E) and then other random city names until County Line Rd (11000 E).
Then there is Congressional Island where all the streets are named after former Congressmen except for Island Ave and Sanctuary Ave.