Turnkey property companies and broker/property managers have both become popular because you can align interests very well with everyone.The key is a lot of due diligence.  

As for some of the other commenters here, the idea is this:Buy a small multifamily in year 1Buy a larger multifamily in year 2Buy a great, large, nice multifamily in year 3Buy a small commercial property in year 4Buy a larger commercial property in year 5This is to be done with conventional financing, using cash flows from previous investments, and is in contrast to the widely popular strategy of accumulating SFRs in the manner described below:Buy 1 SFR in year 1Buy 2 SFRs in year 2Buy 3 SFRs in year 3Buy 4 SFRs in year 4Buy 5 SFRs in year 5I know that real estate doesn't work out exactly like this, but please understand the argument that I'm trying to grasp are the economic advantages of purchasing a large number of SFRs, vs buying just 1 property or so per year, but buying larger and larger each time, snowballing NOT into a vast number of houses, but instead into an equivalently large dollar volume of real estate assets, but with fewer properties that offer economies of scale.

The quitclaim is very popular b/c it's so easy for one to draft up and do on their own for a couple bucks.  

Buffalo is one of the most popular markets people contribute to on Devmap.io!

I know the REI meet ups are popular and I have attend the one in Frederick last month. 

Finding a university hospital is another popular letting market that can command slightly higher rents and very stable tenants that work a lot so less wear and tear on the property is seen.If I were looking for an investment from a distance I might be inclined to look for a family BTL over a student house as the management and maintenance is often more simplified.

Primarily a specialty market I assume for those environmentally obsessed renters.It's a interesting concept but not really popular enough to generate higher returns at this time I would think based on higher initial costs to build.

My wife is from Canton and that area has started to get a little more popular.  

@Nick Cucci Indianapolis is an extremely popular investment market due to the affordable prices and cash flow it offers.

I called a popular Property Management company in the Twin Cities (Renter's Warehouse) to use as a comparison to me self managing and doing all of the work.