Atlanta is one of the largest cities in the country so you have nearly unlimited options for a party venue. Intimate gatherings are a lot of fun in private restaurant dining rooms. If your smaller event isn't about food, then why not book a good time at a karaoke bar or mini golf course? You can even provide your own catering and drinks if the venue allows it.
For larger groups, consider reserving an event hall, conference room, or hotel ballroom. These have flexible seating arrangements so you can more comfortably house larger groups of people. Many are also historic venues, like The Whitley in Buckhead. You can take a brief moment to relax during a multi-day event with spas, fine dining, or tea time here!