The railroads are not yet up to snuff to efficiently travel from Tallinn to Riga. Your best choice is to take the bus. Multiple lines operate this route. If you are staying in Tallinn’s Old Town you can either take a bus from the ferry terminal or the Tallinn bus station. There are more departures from the bus depot than the ferry terminal. Problem here though is that the bus station is over a mile walk from the Old Town. Not an easy walk either, it involves crossing many multiple lane roads, busy intersections and does not present much scenery . Best choice is tram 2 or taxi. I opted to take a cab. This took about 10-12 minutes from my hotel in the Old Town. I should have confirmed the price before because there is no meter and I got charged €15. It should have been under €10 I’ve been told, oh well.
I chose to use Ecolines . This bus company had a better departure time for me and the total price for the 4 and 1/2 hour trip was only €14. ( €15 for a 10 minute taxi, €14 for a bus thru 2 countries ) A bargain for what you get. The bus does have a bathroom, 220V outlets and wifi, yes, wifi the whole way . Though I would charge any phone or iPad before the trip. I plugged in to charge my iPhone and it had what is called “dirty power” where the hertz are not steady and my phones screen began to shake and become blurry.
It had been years since I had been on a bus for any type of extended distance and it was more enjoyable than I remember. Going from one city to the next, the bus allowed me to view some of the country side of both Estonia and Latvia. The bus stops at station about halfway through the journey for a few minutes allowing people to stretch or grab a smoke. Just remember it is over a 4 hour trip so be sure to bring something to drink and eat. Decent sandwiches to-go can be bought at the depot in Tallinn. The scenery, once we were in the country was a dark snow covered forest, similar to pictures I have seen from Siberia. Tall pine trees encased in snow and ice look frozen in time. I took a picture and the color photo looks more black & white. It may be through glass but the views are awesome. So, if you are like me and are used to taking the train to go similar distances through Europe , you will have a pleasant journey, scenic , comfortable and easy, just cheaper.