Expat investors in Greece, Madrid, Portugal?

[Yosi Mizrachi]

I'm looking for future investments and would like to find some information from people who already have experience with these markets.

What are some regulations I should be aware of and how to find this information?  example:
* I know that Madrid has some high tax on the rent for expats, around 25% so I've heard. 

What are the notions as outlook of the markets, does it feel like a safe place for investments? 
Are there any number to back up such notions?

I would love to hear any tips from you guys on one of these markets, let's chat!