Many many new hotels are build in Tallinn. You have lot of options, where to go. There is a popular hotel Viru Hotel, as the centrum of Tallinn. It is in the same building with the big shopping centrum called Viru keskus. Under the building you can find the main bus station of Tallinn's public transport. If you want also relax in your hotel, try spa hotels. One great spa hotel next to the harbour is Tallink Spa & Conference Hotel. It was opened in 2007. It is modern romantic hotel with 10 different saunas and big swimming pool with bar.
If you are going with your family, try Kalev Spa Hotel. There is a big water park for children, spa center and fintness center for adults. The hotel is located near to harbour, near to Old town. If you want quality and full service, luxury hotel Radisson SAS or Swiss hotel are great options. Or traditional Olümpia Hotel. Old town has many hotels with the atmosphere of Middle Ages and magnificent wiews. Remember that many hotels has also an age limit.