@Dariush Vaziri if you don't mind any work, I'd look in PG close to the border - Capitol Heights, Temple Hills, etc - might need small upgrades.

DC, PG County and Baltimore are where BRRRR is possible.

Here in MA I order a title exam and am provided with copies of the deeds in the chain of title, the mortgages etc and a cover sheet with notes by the examiner like "Discharge at Bk 1234 Pg 10 appears to have wrong party", then I look at the copies and have to decide if it is really an issue and if so how it can be fixed going forward in order to close.Maybe you need to order a different type of report.

I am looking for your advice on what cities in PG county are good areas to buy fix and flips and what neighborhoods in DC are good for the same?  

PG’s are not allowed in these.My advice, Austin, is to focus on obtaining competitive money and profitable properties.

Maryland side, I think of Frederick, PG county. 

The U.S. taxpayer identification number (TIN) of all parties to the transaction must be on the application for a withholding certificate (pg 2)”https://www.irs.gov/pub/irs-access/f8288b_accessible.pdfThe IRS is trying to make sure they can chase whoever has custody of the funds owed to the IRS and they do that by mandating the SSN.

Montgomery County you will in Takoma Park, PG County a few here and there. 

I thought I saw somewhere that the required Notice in Maryland or PG county changed for month to month tenancy from 30 days to something longer..

No PG