Tallinn is a fantastic city. You can tell just by looking that it has come the furthest since the Soviet Union epically discombobulated. I call it the result of Finnish tourism, while others might attribute it to sound fiscal policies and the fostering of innovation. Whatever the case may be, Tallinn has the modern feel that its Baltic counterparts, Riga and Vilnius, do not.
The Estonian capital also wins the Old City competition. Come to Tallinn and you'll find the old city perch on a hill overlooking the sea. Stay in Riga or Vilnius and you'll notice that the old cities are situated very ordinarily.
Unfortunately, and this I know is a result of Finnish tourism, Tallinn boasts the highest prices in the Baltic. I was shocked. Nine bucks for a little fridge magnet? Egregious. Exorbitant. The city had one hand in my wallet, err...bank account, the whole time I was there.
Food-wise, it's hard to give the nod to any of the Baltic capitals. I found the best local food in Vilnius, but Tallinn offered much better foreign food. Most of the local restaurants in all three cities are a disappointment because they get the price-quality thing all wrong.
In terms of a "Soviet footprint," it's hard to say who wins. Tallinn doesn't have any evidence of Stalin and company within a few miles of downtown. Get out to where all the big box stores are, though, and you see apartment block after apartment block. In that sense it reminds me of Lodz, Poland.
Overall, I'd say Tallinn is the best of the three Baltic cities, especially in terms of livability. If it wasn't for the damp dark winters, I might move there in a flash.