PAYDAY: The Heist may lack alot of the content its sequel has. However it's more then makes up for it with the being consistent in it's vision. Where as PAYDAY 2 became a bloated mess overtime and PAYDAY 3 is... PAYDAY 3. PAYDAY: The Heist has a clear vision as a hardcore co-op shooter whist being a tribute to action heist movies from the 2000's.

For that alone it is my favorite in the series, and i implore you to give it a try yourself. The heists themselves may be in PAYDAY 2 but it doesn't capture the same vibe this game had in the first place.