i haven't bought my dress yet either, but i have been to 4 different shops. 3 i went with my mom and the salesgirls all said they think it's better to go with one person instead of a big entourage like you see on 'say yes to the dress'. i did go to a store alone and it wasn't bad, it was kinda nice actually. i forgot the camera though so i couldn't get any pics of me in the dresses i tried on. good thing is that place is by my work so i might go again on my lunch break so i can show someone. if you do go alone just bring the camera, it really helps when you can keep track of the different dresses you liked to reference later on.
good luck!