@Dennis Nikolaev I think the best best is to work backwards! What I mean by that is ask yourself what are you looking to get from pulling the equity out.
The broad question of what to do makes it more challenging. If you are looking for cash flow, a multifamily or mobile home park may be the best option. If you are looking for appreciation, you may want to consider buying in "up and coming markets" (or what is considered, "up and coming") in todays market. Maybe you buy more houses like you have.
We are going through a similar situation now, we have the opportunity to flip or assign 3 contracts on larger multifamily properties (probably assign for 1.5 million) or we can purchase the deals and operate them. The question for us is 1.5 million today and invested in a better asset worth it or are these turn around deals make more sense for 5-7 year holds.
Always fun to brainstorm and think of different things. In the end I like to work backwards and model out each scenario to see what checks the right box! Good luck, and a great situation you in.