Wow!
We didn't really know what to expect, but we were very happy with our stay at the Reval Central. The location is superb - only a few minutes walk from the Old Town and less than 10 minutes walk from a huge supermarket. The staff was very friendly, very helpful and the front desk staff all spoke English.
I have to echo things that others have said: the breakfast IS superb, with a huge choice. They have a kids play section with toys and crayons so we could eat while the kids played (though there was too much playing and not enough eating!)
The rooms ARE a bit spartan, but quite comfortable. We booked a triple room with a baby cot and it was pretty large. If you can't get a family room, you could comfortably sleep two adults and two kids in a triple with an extra bed.
There are other nice touches -- there's a free internet terminal in the lobby, the hotel bar is a nice place to sit and have a drink, the entire hotel is very kid-friendly. It's a 15 minute walk (though not well signposted) to the ferry terminal, which will take you to Helsinki among other places.
The staff, the location and the value for money at the Reval Central can't be beat. Highly recommended!