The Best Western is an old prison, so if you want to experience staying in an old prison with quite small rooms (double the size of the original cells) and small windows, in a residential neighbourhood about a fifteen-minute walk from the city centre, then the Best Western would be your choice.

The Radissons are decent but not luxurious, your typical "four-star" Scandinavian hotels, ie not really four-star, but not three either. Something like four-minus perhaps.

The Plaza is at the remotest corner of the Railway Square, and whereas Helsinki is quite safe, you might not feel happy walking across the square late on weekend nights. If you don't plan on taking late walks, then that would be my suggestion due to the very central location.

The Royal is in the Kamppi district, a mix of residential and office buildings close to a big shopping centre and about a ten-minute walk from the heart of the city.

The Hilton Strand is further away from the city centre than the two Radissons, but classier.