Let's say I had a good conversation with another person. It had a good flow to it and it didn't feel like it was just one sided.
Is there an adjective or an adverb to describe this kind of conversation?
I would suggest bilateral communication. Edit: Or, unilateral communication for the opposite.
a productive talk. TFD
- Marked by abundant production or achievement:
- Yielding favorable or useful results; constructive:
We had a very productive conversation!
I suppose the opposite of a one-sided conversation is a two-sided conversation, but it’s not very common or idiomatic.
My first thought was balanced conversation, which does at least appear to be used in several articles, and sounds idiomatic to me.
You already provided the answer in your own question: a good conversation.
The very definition of conversation (per Merriam-Webster online) is an "oral exchange of sentiments, observations, opinions, or ideas."
Although the phrase "a one-sided conversation" is often used, it doesn't actually make logical sense. A "one-sided conversation" cannot be a conversation—as it wouldn't involve an "exchange". Logically, it would be like saying "a silent musical." Instead, it would be more accurate to say that the person attempted to have a conversation but failed.
Idiomatically, however, nobody misunderstands what a "one-sided conversation" means.
So, try a synonym like dialogue: "an exchange of ideas and opinions."