Northern Armenia

Aside from the numerous vans marshutni and buses headed towards Yerevan Երեվան, which you can hop into, you can take a taxi, or if you're really adventurous and have too much time on your hands, take the train which goes Alaverdi-Vanadzor-Gyumri-Yerevan and reverse to Tbilisi. You can also catch transport to Tbilisi from many towns in northwest and northcentral Armenia. From the northeast you can catch transport to Lake Sevan.