The city of Rensselaer, NY has a number of sites listed in the state and national historic registers. Here is a brief virtual tour.
10 Riverside Ave., Rensselaer
Crailo was a fortified colonial home on the Van Rensselaer estate of Rensselaerswyck. It is now maintained as the Crailo Museum by NY State, and will open this year on July 4th weekend. According to their site, "Crailo was built in the early 18th century by Hendrick Van Rensselaer, grandson of the First Patroon. Hendrick died in 1740 and his eldest son, Johannes, inherited Crailo. He remodeled the house and added an east wing in the Georgian style, reflecting the increasing influence of the English on the Albany-area Dutch."
Corner of Riverside/Broadway and Aiken Aves., Rensselaer, NY
William Aiken came from Dutchess County as a young man, and purchased land from Patroon Stephen Van Rensselaer III in 1810. Aiken divided his plot into building lots and re-sold them, becoming a founder of the Village of Greenbush, which was incorporated in 1815. Aiken built his home in 1816, and it was considered the finest on the east side of the Hudson. The house is now privately owned.
Washington Ave., Rensselaer, behind Franciscan Heights Senior Community
William Patterson Van Rensselaer [1805-1872] was a son of Stephan Van Rensselaer III, and inherited of most of Rensselaer County. William built the Greek Revival Beverwyck Manor in 1839. Beverwyck was known as the East Manor (the Van Rensselaer's West Manor in Albany has been demolished). The manor was purchased by Paul Forbes in 1850 as a county seat, and became known as Old Forbes Manor. It remained mostly unoccupied through 1910, and was finally sold to the Order of Franciscans for St. Anthony-on-the-Hudson Seminary.
11-13 Forbes Ave, Rensselaer, NY
This hotel and tavern was built around 1791 near the North Ferry landing in Bath-On-Hudson, on a parcel granted to Jeremiah Clark by Stephen Van Rensselaer III. The second floor was originally a ballroom, but was later divided as living quarters for the tavern keeper. The guest rooms were in the half-story above. From 1839-1867, James Dearstyne was the owner/proprietor. The Dearstynes ran it until the 1890's, when it was the Dearstyne-Miller Hotel. It continued as the Miller Hotel until the 1920's, and was a neighborhood tavern from the 1950's to it's abandonment in the 1980's.
Patroon Agent's House and Office
15 Forbes Ave, Rensselaer, NY
The Casparus Pruyn House and Office was near the former ferry slip and the Dearstyne Inn. It was completed in 1839 for the rent collection agent of William Van Rensselaer, son of the last Patroon of Rensselaerwyck. Efforts by this generation of Van Rensselaers to collect manor farmers' rents (long ignored by their father Stephen Van Rensselaer III) precipitated the Anti Rent Wars and led to the end of the patroonship system in NY. The house and office are now separately and privately owned.
W.P. Irwin Bank Building
156 Broadway, Rensselaer, NY
This High Victorian Gothic building was constructed by William P. Irwin in 1873 as the East Albany Bank & Trust Company. Irwin had an estate in Greenbush Heights, and he owned flour mills, grain elevators and a malt house. Although it was successful, the bank was closed when Irwin died (a few years after it was built) and the building became the jewelry store of Max Hackel and Son. It is now owned by Terance M. Ruso, Certified Public Accountant.
UPDATE: A member of the Facebook group said that the Irwin Building housed the National Commercial Bank and Trust Company for a time as well.
Wikipedia's National Register of Historic Places listings in Rensselaer County, New York
National Register of Historic Places - Rensselaer County
New York State and National Registers of Historic Places Document Imaging Project [Click the Basic Criteria tab, pick Rensselaer for the County, and click the Results tab)