sale of personal residence - sold for $ 1,2000,000/- bought for 510000/- M/F JOINTLY STAYED FOR MORE THAN 30 YEARS - WHICH FORMS TO USE FOR 1040 BASIC

"bought for $450,000/- in 1995"

28 years.

Their initial purchase price + improvements (not regular repairs) = basis, and they might be eligible now for the $500,000 max exclusion from income tax on that gain from the sale. I recommend digging into the improvements, to see if there is an increase in basis. For example, it's not unusual to move into a house and "finish" it, such as that final bathroom, a nicer laundry room, a covered front entry, a pool cage or expanded patio, a real deck instead of a stoop, etc.

An interesting assortment of questions from you for the last 3 years, but I'm not going to assume that you are not a paid practitioner.  I'm just going to suggest you don't charge clients if you put extra zeros in the amounts you enter on their returns.   

If you are looking for support as an individual taxpayer. Please visit the TurboTax Help site for support. 

"....which forms to use" 

F 8949 > Sch D > 1040

Tho some folks say nowhere it there's no taxable gain.  YMMV