Bret Michaels -- Nothin' But A Good Time In Awesome New Crib

Block parties in Khloe and Kourtney Kardashian's 'hood just got a whole lot more fun ... now that hair metal rocker Bret Michaels is calling the place home.

Real estate sources tell us the Poison lead singer dropped $3.05 million on a 6,797 sq. ft mansion in the gated Oaks community of Calabasas ... and has been busy making some rock star renovations.

We're told Michaels got a deal on the crib ... since it was originally listed at $3.475 mil. It's got 5 bedrooms and all the amenities ... courtyard, spa, "multiple seating enclaves" ... and a loggia (rich people word for 'covered patio').