50 Cent -- Takes a Vodka Shot ... At Diddy (VIDEO)

50 Cent shamed Puffy Saturday with a show of extreme vodka support ... at least that's what 50 says.

The empresario posted video of huge lines outside a liquor store in Temple Hills, Maryland with people itching to score a bottle of Effen Vodka, with 50's John Hancock.

50 then Absolut-ly takes a shot at Ciroc and Diddy.