How to compare returns + make critical investment choices

[Phil Carpenter]

Team - I could use your help! I'm evaluating a number of different real-estate investment decisions and am trying to figure out what is the best indicator of returns that I should use to make "apples to apples" comparisons and prioritize my investment choices based on those returns. 

I'm currently doing some residential real estate work with a friend (buy/demo old homes, build new ones, sell them). I'm also looking at:

1)  A fund that buys residential mortgages

2) A fund that buys apartment buildings

3) A fund that buys mobile home parks

4) A condo in Mexico (for rental, not personal use)

5) Buying my own mobile home park

So do I use ROI? But then how do I account for the depreciation benefit that I would get if I purchased a mobile home park (this latter point is confusing to me, and the key driver of this post)? Do I use a measure that accounts for taxes, such as Cash Flow After Taxes? Should I look at CFAT/purchase price as a return measure of some sort?

Thanks in advance for your advice!